Newer model with disc brakes? no way for me bro!
The older model TW's were built with much better built quality than the newer ones and they are also more powerful and responsive because of their slider carbs and type of CDI's that they have.
On the other hand there is usual some small niggles to be sorted out with the older bikes, like cleaning and de-rusting the fuel tank and carburetor, maybe the CDI needs to be replaced and I'm 99% sure that you're going to have to replace those tires also.
My advice is that if you don't mind wrenching then go for the older model, but if it is not your thing to trace down and fix problems then rather get yourself a new TW
I found a list of just about all the differences between the various models over the years, thanks to the late lizrdbrth, one of the legendary members of this forum