my 210 is probably as good in most areas as most of the competition, and better in some
That's correct; additional mission capability will come only from specific additional performance or equipment.
1) Operating ceiling (if you can do 20k then only a turbo engine will improve on that, but at substantial costs and bringing significant oxygen flow rate issues)
2) Climb rate (if you have 250HP then that will fix the climb rate for a given weight, more or less)
3) De-ice / anti-ice ?
But, if everybody looked at it that way, they would all be flying 30 year old planes, because there is not one single thing in e.g. an SR22 that gives you additional mission capability
