People are going to tell you what they have is what they will use for the rest of their lives. It's called "confirmation bias." They have no experience with anything thing else. I've used the 155, the 366 and the Spolar. In that horse race, Spolar wins by a mile.
Not everyone. I loaded on 600 Jr's when I first started because that was all I could afford.
When life got better, I moved to Grabbers and might have fallen into your category, however, a shoulder injury made me think about reloading issues down the road when I got older.
When a good deal came along for a used hydraulic MEC in 3 gauges, I made the move so that I wouldn't have to deal with a big expense after I retired.
As far as comparing to other brands, when you drive a $200,000 Ferrari, switching to a $400,000 Lamborghini doesn't provide any additional value to the driving experience.
In the same way, moving from a MEC hydraulic to a Spolar hydraulic would not give me a better experience.
In this case, the Spolar isn't any faster than a MEC, and I can't think of any issue I have with my MEC that might be a non-issue with a Spolar.
If you really want to get down into the weeds, with a Spolar there's a longer wait time for repairs.
The only upside I can see to a Spolar when compared to a MEC is you only need one loader and then you can add the various gauge heads.
How the loader is constructed or the type of material used for that construction is irrelevant. I don't think I could wear out my MEC in two lifetimes!
Proper maintenance and replacing parts as they wear out should make a MEC or a Spolar last forever.