My K2500S (w/KDFX) is still one of my primary studio tools, and will still give anything contemporary a good run for its' money, but live, it's a pig unless you have everything worked out in advance. My playing style relies heavily on each hand doing something different, and creating splits and layers on the fly is simply not a task you want to do while the bandleader is counting the song in!
I agree that the B3 sim is great (the KDFX Leslie is a big improvement over stock) and I have a sample collection of drawbar registrations sampled from a B3 pre-Leslie that when you run them through the Leslie sim, does as good a job as I have heard most dedicated clones do.
However, surprisingly enough, there's quite a few sounds in my G70 (including the main piano) that most producers prefer over my tried and tested Kurzweil ROM sounds. Some brass, some saxes, guitars, basses (w/SRX board), all kinds of things. Nowadays, my MIDI productions are running close to 50/50 between the two, at least as far as ROM sounds go...
But my K2500 is getting on, I've had it for at least 15 years, and I don't see me EVER replacing it. That's what I call value for money!
_________________________
An arranger is just a tool. What matters is what you build with it..!