I've built motors with CTR pistons and b16a pistons and they (ctr's) are not worth the trouble. Alot of detonation issues, timing had to be pulled all over the map to get them to run good on 93 octane and then it would still detonate occasionally. Another thing to note is that by law octane rating only has to be +or- 4 points. So that means you can pump "93" octane and still really only get 89 octane and that is considered qacceptable by whoever regulates those types of things. And when you consider octane costs money I highly doubt the manufacturers are on the plus side of the deviation.

The only time I'd suggest running over 12:1 on a daily driver is if you have a seperate race gas tune that you will run. Otherwise what is the point of running 13:1 compression if you are going to have to pull timing and detune it to run on 93 octane. You will make just as much power running 11.5:1 and decent tune.