Caster Camber plates, 3-bolt vs 4-bolt. What's the difference?

4 bolt is stronger. It is basic physics. four mounting points on all coners is more rigid than 3 points in 3 of the four corners. the fourth bolt is really only a "must" have if the car is driven very hard or you are running coil overs IMO. I am glad I got four bolts becasue I am going to switch over to coilovers I think and now I don't have to get new CC plates.

my advice would be maximum motorsports or qa1 CC plates. but then again it depends on how hard you drive the car but from an engineering standpoint I like those two the best and I looked at all of them.
 
4-bolts are a bit stonger, and better if you are doing Coil overs. 3 bolts are fine though. With Coilovers, a lot of stress is put on the strut bolt. With 3 bolt plates, all 3 bolts lie to one side of the Strut bolt. This is fine for stock spring locations, not good for CO. 4 bolts are also more difficult to install as they require some drilling.

I went with the maximum motorsports plates for the adjustability, reputation, and 4th bolt.