My girlfriend and I were shooting a friend's GLOCK 19 with Storm Lake barrel a bit this past weekend. I put a couple videos on youtube.
http://www.youtube.com/watch?v=nBsBQEmDQwI&feature=user
http://www.youtube.com/watch?v=pzJ__4o1NI8&feature=user
I have shot the GLOCK 19 with the Bar-sto barrel as well. Another friend of ours from the range has one. I could not really tell the difference between them two barrels - other than that one says "Bar-sto 9mm" on the top, and the other one says "GL19 - 9mm", just like in the pictures above. I think they are both a solid product. Both seem to be more accurate than the stock GLOCK 17's.
Here's how I used to shoot my GLOCK 17 with the stock barrel:
This was one of my first times trying a G19 with the Bar-sto barrel. That is 10 hits - nearly all touching. The hit that the ruler is partly covering is a stray hit from something somebody else was shooting.
I would have some G19 with Storm Lake targets for you as well, but my girlfriend hit my target I was going to use with a bunch of stray shots! So maybe next time. I found it to be shooting well. I was a little low and to the right (stock GLOCK sights, which I don't like) but it was grouping fairly tight, circular looking, sub-3 inch groups at about 15 yards, so that is good for those guns.