Seems to me that you just want a fast booting computer, buy a PDA
Curiously, I had that thought at one point. I bought one and returned it within a week. The problem with those critters is lacklustre handwriting recognition. While it works perfectly in the store, it wasn't suitable for even a mild workload. The screens are pitifully small too. And the internet connectivity isn't ideal.
I looked at the software lists for Amiga OS 4 and Pegasos and must say that it was less than impressive. The problem wasn't so much the lack of software, but what it was. Games and emulators, while entertaining, are a bit frivilous at this stage of the game — particularly when you have an excellent library of legacy Amiga games to choose from (well, I guess you'll need UAE for some of those games).