fwiw, I do have a keithley 2015thd (similar to 2000) and I like it a lot, but I also knew it was not fixable, for the most part, other than swapping out the bad caps (which I still have yet to do..).
most of the comments here are favorable to the hp unit and so maybe I'll try to prefer that one for the next time around. hp does not always make great stuff, but it sounds like this was a reasonable design and implementation, which is great to hear.
(one thing the keithley does have that the hp does not is a thermocouple mode. I am doing some temperature sensor stuff these days and when I connected my fluke banana-plug based tcouple into the keithley I was surprised to see so many digits after the decimal point on that device. a nice extra feature to have, to be sure.)