HELP! on TWgs and ZIPgs

[joshua@sumax.seattleu.edu (bar joseph)]

I realize that perhaps this is an O-L-D subject and I might be wasting
bandwidth, but I thought this would be the best place to ask, so here I
go.
I've been trying to buy an accelerator board for GS.  I guess it's common 
knowledge to buy ZIP over TW, but I've recently found a great deal on a
used TW rom 1.5 (8k I suppose).
Now the question is...  should I just go with a great deal, or should I
buy what is worth the price.

Therefore, I would GREATLY appreciate ANY information regarding..
  1) pros and cons of TransWarpGS
  2) pros and cons of ZIPgs (if there is any)

The MAIN things I am concerned about are the compatibility of TWgs with
mainstream hardwares + softwares, AND the efficiency of both boards in
comparison.

ALSO, if there are any kind TWgs users who can tell me more information
such as installation and common problems+answers, I would be very
thankful...it seems that the TWgs I'm considering to purchase doesn't come
with a manual.

THANKS in advance for ALL the help!!!

Pete
IIgs forever-