Couple of thoughts here.
First, just like boats, there's no such thing as the "perfect" rig. Every one of them will involve compromises, some major, some minor.
Second, Yes, of course there are differences. We would love to change many things about our coach. My wife would LOVE a king bed. I'd love diesel power and air suspension. We'd love an oven in addition to our micro/convection.
What we do is this. When we get the "bug" to upgrade, we go look at coaches that have exactly what we want. Then we sit down and say, Ok, for us to upgrade, it's our coach PLUS whatever the new coach would cost. So if it's a 100K used diesel pusher that has all of the "wish list" in it, we say ok...we could get $XX for our coach, they're asking $100K for that coach, could probably get it for $90k, and the delta is?...say it's $35K.
We then ask ourselves...as much as we LOVE our coach, are the upgrades worth spending $35K on? Another way to do it is to say Ok...you just won a big prize. There's $35K in cash sitting on the dining room table. Would you use it to upgrade the coach, or would you use that cash for other things like retirement, travel, etc.
For us, the answer has been to keep our coach and not spend the extra money...SO FAR.
That being said...situations change. In 5 yrs I will likely retire. At that point, one of the options on the table is to full-time for a year or so. THEN we would likely look to upgrade for some of the things we'd like.
In our current situation, we just can't justify the expenditure.
There's a lot of moving parts in this decision ;)
Jim