I haven't had a chance to evaluate the Studiotek 130 personally, but I've not been terribly impressed with Dalite. The samples I've seen... are too 'glossy.'
Glossy isn't the right word, but it's the only one coming to mind right now.
On the other hand, I do have this observation:
For the last couple of years at a major industry trade show, Draper, Dalite, and someone else all had booths. Stewart did not.
On the other hand, anyone showing off a projector had a Stewart screeen.
The catch that I know of with Stewart is that they are horriffically expensive.