Whats the difference? Is it worth the extra $? Is the ULS more prone to streaks?
I have only bought the ULS and no matter where i buy it it always has streaks. So im just wondering if the standard UL is any better???
Thanks.

I have never used the ULS in clear so can't say about the streaks.  My understanding is that ULS is a little less likely to crack or split around limb bolt or alignment pin holes. Never had any problem with the ULsplitting as long as I am careful.

ULS has scrim.  You can see if if you really examine it closely, it will show up as a fine, thin weave inside the glass which is intended to provide cross se tonal support.

I hAve  typically bought ULS.    But this past summer I had a good conversation on with a long time bowyer that I respected very much.  In that conversation he convinced me that the added scrim in ULS is not required as today's fiberglass is not prone to the longitudinal cracking of yesteryears glass.  After reflecting, I would have to say that I never had a glass bow with UL glass crack.

I think from now on I will save the extra $ and just buy UL.

Yes and if you do the maths it doesn't add hardly any lateral stability. A little bit of marketing that one!