I'm a bass player, and I notice a huge difference between original and second generation T's. The second generation has the mid selector switch, and the mid boost is always on. Might be fine for guitar, but sucks for bass. I did a couple of the mods on Joe's site, cutting the wire and bypassing the mid boost, and it's a far better amp now, for my purposes. And I can still crank up the mids for guitar use.
And yes, the Fender-era T is a completely different animal. From everything I've heard, it's a fine amp, but nothing like the old Model T amps.