I investigated a lot and bought a used DELL AT101W a while back unfortunatly the backspace key and the '8' does not work. The keyboard does not fell that well either when typing.
Now I am considering an Unicomp Spacesaver or an ABS M1... I like the idea of the old style keyboard with click like my old Cherry Click keyboard or the one that I had on my IBM PC10, but my concern is that a buckling spring keyboard is not useful for gaming at all...
How long did you use the AT101W for? It can take a month or so to get used to a new type of keyswitch so if you only had a quick play with it because of the broken keys I suggest you remap the backspace to something else (e.g. caps lock) using
sharpkeys and give it a good trial.
The ABS M1 uses a newer version of the switches in the AT101W so if you don't like that then the M1 might not be for you either.
You also need to mention which country you're in as different keyboards are availible and different layouts are standard. This thread is about someone looking for a good keyboard in Britain, so that what I assumed initially but as you bought an AT101W and are considering an ABS M1 I assume you're the US or Canada, or somewhere else that uses the same layout and you're willing to import.
EDIT:
Stiggy: Unfortunately, there doesn't seem to be much in the way of high-end keyboards availible here at the moment. As you didn't want a german keyboard because of the symbols I guess the Das Keyboard is out too, and the 'left-handed' keyboard is out if you want an absolutely standard layout, which really just leaves the G80-3000, a Unicomp and the AT102W
The G80-3000 is apparently well enough built for it's use and isn't likely to break down, but doesn't feel solid. I can confirm this with my experiences of the G80-1800. I don't know if that's an issue for you.
I can't speak for the build quality of the unicomps, but it looks like the price for a customiser is around £85 now with shipping and customs so it's a fair bit more than the G80.
The Dell AT102W is well built, but you will have to either wait a couple of months for one to come up on ebay or go hunting round the local second hand/charity shops to see if you can find one.
There are several keyboards using Linear Cherry MX switches, but they're not terribly popular and none of them have entirely standard layouts.