The 950's are generally considered to be faster than the later 990
the 950 is carbed the 990 inj I have ridden both and thought they were equally quick .
its a v-twin that loves revs and keep producing power .
For hours of reading about them look here
http://www.advrider.com/forums/forumdisplay.php?f=34
service interval is 4000 miles chain drive not shaft (big deal most of the bikes I have owned were chain drive)
tyres are tubed oe being pirreli scorpians mt90 feel fine at my limited pace
the 990 is a smaller bike than the 950
the s version is taller.
the s version of a 990 is the same size as a non s 950 .
the 950 s is a monster (thats mine
)
earlier models hhad a 3 year warranty later ones 2 years .
if you bought an 05 950 it would still have some left .
Genrally they are cheaper than the GS and some would say not as good .
personally I love it .It is more involving to ride than the BMW.
Can see why anyone would own either . At the moment I prefer the KTM
but then I have had three GS's so it is a pleasant change and a bit different