@Paradox
A Pegasos1 with G3/600Mhz has to skip frames to emulate an A500 at full speed. Maybe Efika memory controller helps a little, but don't expect to be able to emulate AGA games smoothly unless Bernd Meyer releases his m68k JIT emulator for PPC. Now that OS4 final is out maybe he gives the sources to Richard Drummond so he can integrate it into E-UAE.
Piru is right: You won't be able to run smoothly games/apps designed for anything faster than an A500 and you may have difficulties running A500 games that require cycle-perfect syncronization.
On the other hand MorphOS is enough light to run apps like Mail/Web browser/etc smoothly on a 400Mhz 603e without L2 cache.
BTW... there's nothing special in running UAE... any off the shelf pc can do it. A500 games ran smoothly on a P233MMX with "Fellow" (an old A500 emu). Efika will probably run UAE slower than a 400Mhz Celeron.
If Bernd Meyer released his PPC JIT and Richard Drummond integrated it on his E-UAE it would be a revolution for Amiga emulation on PPC. I guess that an Efika could easily emulate AGA games that don't require perfect sync if E-UAE used Bernd Meyer's JIT for PPC.