I've used Giordana shorts in the past (Lasers, mostly) and loved them; used them until they wore out. Some of the reviews for 2014 Laser shorts were less than enthusiastic, though, so when the time came to refresh the supply I switched last year to Castelli Free shorts (the decision was also based on some great sale pricing). While I've liked the Castellis, I find their durability to be less than ideal, and end up fighting a saddle sore whenever they show just a little too much wear.
So I went for a pair of the FRC shorts recently and my butt is ever so glad I did. I took them for their first 50 miles today. For some reason the chamois in these shorts is perfect for me, does not move around when I'm pedaling, and is good for mile after mile. I'm sure it's got something to do with the myriad of technical features listed in the product description, but the fact is they fit great and the chamois just does the trick.
The note about them being "very slim" is true. I'm skinny (6'4", 165-170 lbs, 32" waist) and a large is perfect, but I could see how weightlifter-quality thighs might have issues.