well I can't comment on 4.0 matters as I went straight to OS4.1 quite happily..though keep in mind that when new hardware starting popping up (Pegs, A1's, Sams, new & upcoming Sam460ex and X1000) I was pleasontly surprised that they had time to bring the classic users up to date with OS4.1 & incorporating modern hardware for the classics
I've got be honest here the Natami or the MiniMig AGA are the only possible future for me "upgrading" my Amigas. I've given up on the X1000 and Sams etc... don't really do it for me.
I simply want to be able to run all my old Amiga software like PageStream, ImageFX etc.. a wee bit faster (not into games much) and be able to buy and use new HDs/DVD drives and the like without having to pay 500 quid on ebay for an accelerator board.
Having looked at AROS, MorphOS, Broadway, OS4.1 and such I can now say they are not for me. Strange as it may seem to some I really don't want to run an Amiga that looks and feels like a PC or Mac or even use the type of software that they use. I now have a couple of Macs that take care of that side of things and I'm now even more convinced than ever that the Amiga doesn't need to try and imitate these machines.
For me 25 years of using the Amiga on a daily basis has never lost it's charm and folk can say what they want, but I'm happy using my miggies just the way gawd intended...
