not surprisingly,
its been a natural progression and refinement from Honda thru the frame gens.
Each is overall a bit better than the one before.
Some steps were leaps, some where less drastic,
but still noticable improvements.
all handle better ,and feel lighter than a steelie.
a gen 2 is quite an improvement from a gen 1
The gen1 as noted have an uncomfortable seat/ergos compared to most any other gen
I actually liked the Gen1s just fine!!
and felt at home on them
but i would say they are the least forgiving in setup.
set the susp up properly and they handle quite well

vary even slightly , and thier handling and manners degrad rapidly.
so stay on top of race sag and general set up..
The gen 2 was an improvement in comfort/ergos, and in hanldling,
and you could be a bit off in susp set up,
and it wouldnt get all cranky.
Gen3's were more of a refinement, did improve handling ,
and were not too picky about set up.
they can still handle decently, even if you have the susp pretty whack.
and of course handle very well when set up properly.
the gen 3 on a 125 chassis ( steeper steering head)
(service Honda Limited Edition's, and team trubble recent bikes)
handling was a little quicker than the 250 based gen3..
and did not seem to suffer any loss of stabilty..from the steeper head angle at all. a win - win.
the gen4's (i've only experience on the CRF250R and X based gen 4's )
are very good handling machines,
as they are again at thier roots a quick handling *tiddler* class bike,,
and again a refinment of a long proven chassis design.
The ergos are a bit smaller,
(so big guys *might* feel more cramped)
but the overall feel of the bike is generally more comfy ,
lighter and quicker handling.
The 08 having stabilizer and the 22 mm offset triple clamps-
is noticable over the 05-07s'
It's my favorite chassis by far.
but i dont expect honda to go backwards , and it makes sense that each refinement would gradually improve the overall feel.
and make no mistake, between any gens you can feel a difference for sure.
jump between a gen 1 or 2 and then onto a new 08 gen4,
and its a prettty radical difference.
again that should be no surprise, there is a decade of pretty constant and consistant refinements ,and they SHOULD be noticable....
AJ