i took the prcatice test and was taken aback.
So you took the entire test? Did you get a good score. (The program tells you in the end.) If it is good then you don't need to worry any further. Just do the other practice test and also you an download from that same link the sample paper based test and use that for practice too.
what a v.tough qsand relatively easy qs look like
Umm... honestly, I can't really tell which ones are hard or easy... They all seem pretty much the same to me...
I got 760 the first time I took it (at home) cause I forgot to track my time carefully, so I ran out of time. I haven't taken another one yet.
downloading the grebible software be helpful?
I have never heard of it... But unless your quantitative score is seriously low you probably don't need it.
Honestly, your time will probably be better spent studying for the physics GRE. Hope you have started on that!
Have you checked out the thread with the 2008 applicant profiles?! That will give you an idea of what people get.