Specs:
'Okay, but what does all that mean' you ask? It means faster screen refresh rates, lightning fast rendering (I clocked the cow that comes with Imagine 4.0 at 8.14 seconds, compared to the 26.89 seconds on an 040), faster program loading, and pretty much everything else is just, well, fast (See the benchmark for a better idea).
If you do some serious rendering, or any sort of graphics manipulation (ie. ImageFX), you're going to be impressed when your rendering times are cut down to seconds. Not only that, but with the extra 4, 72 pin SIMM socket's you can add alot more memory to your system.(I've got 48 Megs in my A4000/060). The installation is fairly simple, just pop the front panel off your 4000T, unscrew the brace and pop the 68060 in, (it'll probably take you about 10 minutes), of course there is full instruction's included on how to change the couple of jumpers which you configure according to the RAM your using. The software installation went like a breeze too, I had my 060 running within a half hour.
'What about software compatiblity though?', to be honest I've found that a couple of older programs just won't work on any 68060. Mostly some of those old Amos games (but old Amos games don't work on many systems anyways). Because of Motorola's design on the 680x0 family, about 90% of all existing software should function perfectly.
Who needs a PowerPC when you've got 72 MIPS of power right here right now? And espically with the new low pricing from QuikPak (only $749 if you trade in your old 040), see QuikPak's homepage for more info.