You are correct:
The K1200LT is probably the only BMW where they choose NOT to replace the IABS with next ABS generation (non servos) for 2007 and later. All other large engine models (1200 and up) got the new simpler (non servos) by TEVE beginning late 2006.
Of course, BMW knew very well they were planning to end production of K1200LT in 2008 so why bother with engineering changes for a limited production model - by that time the K1200LT was not selling in very large number.
John you actually thoroughly detailed the difference in a sept. 5, 2015 post, see below:
I see you already got some replies - I will add this as a summary assuming you are based in USA (as Canada and Europe sometimes get these model changes 1 year earlier):
1) 1999-2001: the original model with 100 horsepower and ABS2 brake system (this ABS is simpler and can be repaired for acceptable cost)
2) late 2001 to 2004: same engine and design as earlier but with new ABS system having servos booster built into the ABS modulator. This ABS system is more complex to bleed, more fragile and cannot be fully overhauled in North-America - ModuleMaster in Idaho is working on this project. In addition, you should be aware that when this ABS system fails, you loose 80% of braking power (my own personal estimate).
3) Last generation 2005-2009: new fancy instrument dash, engine has 15 more HP (compression, larger intake...), electro-hydraulic center-stand, steering geometry changed (a bit easier slow speed handling). Same ABS system as late 2001-2004 explained earlier.
In addition to above summary, each generation had various optional equipment from factory that you want to check for before buying:
- immobilizer/alarm: an anti-theft system that is more trouble that it is worth in my opinion. BMW are not stolen like Harleys are...
- radio with or without CD changer: this has been a nice addition but many owners had failure and had to have it repaired or replaced.
- heated seat and/or pillion backrest
- GPS navigator
- Xenon headlight
- Electronic cruise-control (most have it)
- Heated grips (most have it)
- central locking system for all 3 luggages and front compartment (believe was part of the Alarm/Immobilizer package)