The snobbery really does wind me up, and thats coming from someone who used to sell Kleins BITD...
The older ones are definitely special, but to dismiss the post buyout models is madness, they are still excellent bikes, light stiff, great handling and well made, up until about 98 (and even maybe 99) they were still very recognisably Kleins and even if some of the passion had waned they still held on to a lot of the magic.
I spent ages looking for a the 'right' Klein for me, and you know what I was looking for? A 96-98 Pulse, yes that's right a Pulse, why?
Because it is the model closest to the buyout that has 1/18 headtube, to give me fork and headset flexibility (attitude and Adroit ruled out for this reason), normal BB shell, still uses gradient tubing, external cable housing may not be as neat but its a damn sight easier to deal with and replace, has geometry that suits rigid or 80-90mm forks equally well, is still stupidly light (and lighter than later attitudes) and rides like a Klein - great!
Later models did start to evolve into essentially duplicates of the Trek Alu frames, even using the same dropouts and tubesets towards the end and lost a lot of their individuality but they are still very very good bikes.
If my pulse ever dies I'll be looking for another one, (or maybe a slightly later attitude) in preference to the older models with their awkward BBs, headsets, crack prone seat bolts and annoying internal cable runs.
Hate me if you like but I think as actual bikes to ride and use, some of the later models are better options.