The differences between the older models (99-04) and the newer ones (05+) are :
*15 more hp , all in the upper powerband
*second light below the main light - still insufficient
*all new instrumentation / computer info screen - looks much nicer IMHO
*Electro hydraulic stand - nice gettin bike up but gives up a bit of clearance
*slight different front end specs for more slow speed stability - hard to notice
*Riders' seat softer and slightly thinner near tank - most think older one is better
The power, instrumentation looks, and centerstand are all nice to have but honestly the older models feel just about the same to me . You really dont use that upper rpm power most of time, I am a big guy so hoisting the bike onto the centerstand has never been a problem, I like the old seat better .
If you are looking for big differences , IMHO its not worth it. If I was looking to get my first LT , I would try to get a newer one if it was in my budget but if not , the older models are plenty good......I just wish mine were either Canyon red or Pacific Blue, love those colors the best.
Not sure about the hessitation issue on newer models.....the two I road (newer models- only put on a few hundred miles total) didnt have it and my 02 definitely does have it .
Of the older models , the earlier ones had the Brembo brakes (pre 02) . The servo assisted power brakes are quite grabby unfortunately but very powerful (as you know I am sure).