The connectivity of the ASUS (tablet) is poor compared to the ADAM. With the keyboard attached it is a bit better, but still not as good as ADAM.
The screen and resolution on the ASUS blows the ADAM's PQi away indoors, but obviously suffers outdoors like all screens. If you work indoors, ASUS is a no brainer. If you go out a reasonable amount then the ADAM PQi might be better. (I can't comment on the LCD variant of the ADAM not having seen one)
Battery life is better on the ASUS. Add the keyboard and the battery life almost doubles again!
ADAM has 3g capability currently. I'm not sure when the ASUS will get that. However, I can tether using my phone.
The ASUS is much lighter/thinner than the ADAM, but the ADAM feels sturdier. (Don't get me wrong, the ASUS is well built, just not quite to the same industrial standard!)
ASUS is honeycomb out of the box. Not really a big issue if NI release honeycomb for the ADAM eventually.
I really liked the ADAM, but the form factor and keyboard facility of the ASUS convinced me to keep it and sell my ADAM and iPad. I may pick up the ADAM again in a few months time when things have settled down.