Autoloaders and waterfowl?

The last time I used a pump regularly for waterfowl was back in the mid 1980s when I tested a Mossberg 835 before they came out and one of the first Rem 870 Super Mags that hit the market. Since then I've used either a semi-auto or O/U for all my waterfowling. A pump can be a bit more finicky but if kept clean and if care is taken to keep mud, weeds, chaff, etc out of it, it can be as reliable as a pump.
As for the models you mention, my opinions are thus:
I do not care for the Rem 11-87 Super Mag, I personally know of too many having problems with theirs, mainly feeding and ejecting problems. I have not used one while hunting myself but did try one at a range day. I did not like the handling ability but that is a very subjective opinion. Three other people would have at least four different opinions.
The Beretta Xtrema is the one I would prefer as I am familiar with the action and have a good network for parts if ever necessary. Beretta also has a good reputaion for reliable guns and it is borne out by the experiences of three friends with them. I also like the way it handles and it seems to be heavy enough to soak up recoil but light enough for easy handling.
The Benelli is the favorite of a couple friends and is one that all other waterfowl pieces are now compared to. I am not a fan of them as the ones I've used were way too short and needed more work to make fit than I wished to do on a $1000+ gun. Cost is another factor, I don't think it is worth the $300+ dollars extra over the Xtrema and others in this price range. I also prefer the gas operated guns as the Benelli's recoil operated action does little to reduce recoil. Most of all I don't care for the light weight of the SBE as it makes it unpleasant to shoot for extended periods of time. If one is looking for a single dual purpose waterfowl/upland gun the SBE would be a serious contender.
I do not feel the 3 1/2" shell is really needed for waterfowling, I use a 1 1/4 oz steel load in the 3" shell for the vast majority of my goose hunting and do not feel handicapped in the least. This is for birds as close as 10 yards on out to 60. Practice and patterning work is what matters at long range, more so than amount of shot.

I bought a winchester SX2 this summer and have really liked it for duck hunting. Before the Win. I was shooting a Browing BPS. As with any gun, keep them clean and they will do just fine for you. I would go pick up (and shoot if possible) every gun I could get my hands on and see which one feels and fits the best. Most of the autos on the market today are very reliable. It all comes down to fit. The best gun in the world will not make you happy if it doesnt fit you properly.

The 1187 has been around a long time and a lot of people swear by them. Personally I don't like the way they ballance and they are a bit on the heavy side. However, I saw that wal mart has the 3" version in syn. camo for under $500.

A budy of mine shoots a Benelli M1 and really likes it. It is a very light gun that requires litttle maintence. My dad bought a Franchi I-12 this fall. This gun is built around the Benelli inertia system and sells for under $600. It is not as light as the Benelli but functions every bit as good. My SX2 is a gas system and is super easy to clean and is a bit easier on the shoulder (though I can't tell a big difference) than a inertia gun. I don't know about the extrema but being a Beretta it is probably an excellent gun.

Any action can jam because it's dirty. Granted semi auto's are more prone to have this happen than say a pump gun. The better semi auto's can take quite a bit of abuse and still cycle. With a semi auto it's more important to pay attention to to the type of oil and the amount used than on other action types.
I like a 3 1/2" chambered gun myself for waterfowling.

I would go with the Benelli or Beretta off your list of choices.
In my experience the ComforTech is about marketing and not recoil reduction. The removable soft comb is a nice feature of the ComforTech. I have not shot the Kick Off system yet so I don't know.
Both are very good models that will work well for waterfowling and turkey hunting. The Benelli will be a little easier to clean. If you include the recoil springs then the Beretta will be easier. The SBE II holds four shells total to the X II's five and both can take extentions. They both come with shims for the stock and automatic magazine cutoff's. The X II has a bolt lock lever on the left side of the receiver that the SBE II does not have. The X II will more than likely handle lighter loads better. The SBE II is lighter in weight and both have a similar balance with more weight towards the stock. The SBE II has a lilttle smaller feel than the X II. The trigger gaurd is bigger on the SBE II which is nice for gloved hands. The safety size, shape, and location is better for me on the SBE II.

A few other models that are as good as the Benelli and Beretta would be the Browning Gold 3 1/2", Franchi 912, or the Winchester SX2 3 1/2".

I've had no problem with any waterfowl gun if kept clean and parts replaced as they wear.

Pumps (870, BPS, Nova, etc) are great at working in rough conditions--but if abused will balk at ejecting and seating. I saw two 870 single shots this last week--one with a rusted chamber which would not eject Federal Classis Steel and one that kept putting a shell beind the shell lifter (usually this is the result of short stroking the action after curing this problem the gun would not go fullly into battery on the second shot due to a really dirty action.

Auto's this week had no problems--from a ratty looking A5, a pair of 1100 Magnums and an SX2.

The more I shoot from field layouts the more I appreciate a gas operated semi-automatic and may never take a fixed breech gun on a waterfowl hunt again.

A heavy, gas operated, semi-auto is my preference.

I had the same opinion of semis but finally put my 870wingmaster in the gun safe for the first season in 25 years. Semis are addictive and its hard to go back to a pump . Regarding cold weather semis are no problem as long as they are clean.I have hunted without a flaw down to -23 degrees celcius just 2 weeks ago.Lots to choose from but after you look at all the pretty guns check out the Baikal MP-153 (spartan 453). Russian built ,not as pretty as the others but beautiful balance and fit for me and a tonne of features(check out the "I love Baikal" forum at this site. there is a relatively new post on all its features). I was heading towards the Benelli SBII a very nice gun but luckily found this MP153,"the other B gun". It is an under priced overacheiving shotgun.Regarding cold weather I use to bring my pump as a backup expecting the worst from a semi but not any more. Good luck. All the best!

I would have to agree with Denis. Take a look at the Spartan 453 or the Baikal MP153 and save a few hundred dollars for shells. I have owned my MP153 for over 2 years now and still can't believe how well this shotgun performs for a $300 dollar firearm. I like this gun so well for waterfowl that I sold my Beretta 391 Extrema. I duck hunt with friends who own these magnum autoloaders... Benellis, Berettas, Brownings, Rems & Wins... They are all fine shotguns. All of my friends can't get over the dependabilty of my MP153 for the money. My friends refer to my MP153 as the Russian Tank. As for using an Autoloader for waterfowl? A regular cleaning after a day afield and a full strip cleaning at least once a year. I've found the autoloaders I've seen and used as reliable as any other shotgun you can carry into the boat, swamp or blind. I do recommend a synthetic stock model for waterfowl hunting. I love wood but I think the synthetic stocks hold up better under harsh conditions of waterfowl hunting. Best of luck...