main change was carbed to fuel injected Phil - approx 2001 was the changeover
a bit more:
Carbed 600's from early 90's, till approx 98
Then updated (same 583cc) engine for M600, tho is NOT compatible with early engine on internal parts, cyl barrells etc.
Then 2001, new fuel injected M620 comes out - S version has a bit more goodies on it.
Injected tank is deeper slightly, tho it has to hold all the 'internals' - the pump etc. less mpg for an injected bike.
The dark 620 has a plastic tank, which is smaller internally, and single disc & other basic bits etc
can be more of an anorak if you like?
but basically, the 'ie' versions will be more accomodating for a taller person. The 'S' version will be a tad taller still.
The S4/S4R are taller than the M1000/900ie versions, unless the 900 is an S model........
C
[Edited on 6-9-2005 by CK and AK]