powermonger stated it pretty well - as to the differences/advantages of the A1k/A3k/T.
It basically just depends on what your philosophy is - I was able to use my A1200T/PPC/060 through the mid 2000s to do all of my computing work (internet/web/image processing/email, games. demo watching, etc).
Today, using an amiga for modern tasks is nearly impossible (on a native amiga - argue all you want!), so I have since sold all that and I do keep an A1000, 500, 2000, 3000. I keep them because of the memory of them, not specifically because of their capabilities anymore.
Of those, the A1000 is the nostalgia machine - unique design, will run everything through the heyday of the amiga. A2000 probably the most expandable amiga, I keep it around for video toaster, bridgeboard (vortex 486), and also games. 3000 - I believe it is the most elegant Amiga design, and was basically the "end of the line" development-wise for the amiga. Yes, I'm quite familiar with AGA, and it was an 11th hour compromise.
