I know quadrant is pretty cool benchmarking tool but you might want to give this a try too. Grab a friend, load the same movie up on the Gtab and the Transformer, place both the devices three feet in front of you flat on a table and ask your friend which one is better.
I had to return my GTab when my girlfriend commented that having a tablet that can't actually be seen unless held at the right angle directly in front of you is rather useless.
The Transformer is a brand new tablet with an active, if somewhat still empty handed, community behind it. Out of the box though, using the default software, it's an entirely useable system that does exactly what I want it too (in my case quickly display photos, web browsing, youtubing and web surfing). I suspect three months from now it'll have some solid development work behind it since all of the alternatives have managed to overlook the importance of price point as well as innovation in their scheduled releases.