Hi TjLaZer,
The Amiga 2000 is bigger then the Amiga 3000 and 4000 because it has a larger, better designed motherboard. The Amiga 3000 and 4000 has their Zorro slots on a daughter board, a very poor design. The Amiga 2000 and 3000T have their Zorro slots right on the motherboard itself. This is a much better design. Also, if you compare the cases of the Amiga 3000 and 4000 to the Amiga 2000 case, the Amiga 2000 case is much better quality. Also, The Amiga 2000 has a "thru-hole" circuit board, with all of the main chips in sockets. This makes for much easier repair. The Amiga 1200 and 4000 have "SMT" circuit boards, which are lower quality then the Amiga 2000's "thru-hole" circuit board. The Amiga 1200 and 4000 are very hard to repair and are basically "throw-away" boards. People here on Amiga Org have more problems with the Amiga 1200 and 4000 computers then with the Amiga 2000 Series. The Amiga 2000 IS the Flagship Amiga, so have some respect for the old girl.