Im pretty sure someone told me once that it was like 30 or 35 on the bolts on top of the strut towers, but don't quote me on that.
Anyway, I definatly feel a difference during high-speed cornering with my strut bar. the car doesn't dip to one side anywhere near as hard as it did before I had the strut bar. I took the same S-turns with and without the strut bar (actually twice because I had a different strut bar that I didnt like before I got my SPW) and there is a noticeable difference.
If you look on newer cars (after 2001/2002 or so), a lot of cars are coming STOCK with strut bars. I went over my parents house a few weeks ago and they just bought a new-used acura (RL Type-S I think....I hate my dad now cause it is manuamatic...can be slap shift or automatic) and it comes stock with a big ass black strut bar. It's sweet.
For the money, a strut bar is a nice suspension upgrade. take some tight corners at higher-than-normal speeds. u'll feel the difference. just dont fishtale into a tree