Quality of new (say 99 or better) 20 and 21 hulls

[gmcauliffe]

Hello everyone - visitor from ClassicMako here. I finally blew the motor on my old 74 Mako 20 this fall, and am now comtemplating getting something of more recent vintage.

I mostly flyfish the Long Island - Gulls - Block area, and the SeaCraft 20 and 21 models have caught my eye. I've heard they're pretty good for what I want to do, so my questions are more about quality -

Qualitatively, what should I be looking at on one of these recent hulls?
What are the known problems?
Major differences between the 20 and 21 ?
Any reason NOT to buy a recent one?
What is recommended to fix/add/change on these hulls?
Would any of you Potter-era guys buy a recent one?

Thanks much -
George.