After a couple test rides these are fast moving up my preferred chart for hip and leg protection; super light and flexible; more so than some of my riding shorts. However, You aren't going grocery shopping in these yoga shorts.
http://www.storelli.com/bodyshield-sliders.html
Ok test results are in. I have done 800 miles in those shorts now.
1) I road with just them as bike short.
2) I road with them over Triathlon shorts
3) I road with them under Triathlon shorts
The results
1) The are a bit too thin to wear by themselves. I rekon they'd last about a 1000 miles that way. Not really enough leg elastic to keep them in place on the thigh.
2) They fit as a top layer and are comfortable. Being a top layer seems to protect the fabric better.
3) Works great; very comfortable and the bike short protect them. Since they are designed as a soccer under layer they work great.
Final Summary
They have the padding where you need it; no hip road rash if you go down wearing these. The fit under any thin biking shorts and allow you to go to a much thinner triathlon short/bibs or yoga style shorts. They do not interfere with the pedaling motion at all.
I'll be getting a 2nd pair or two for the rotation. Current ones have been washed about 15-20 times and are holding up well; all the fabric damage I see is from testing them as an outer shell.