That reforge optimizer is not working for me at all. It won't import my armory. Because of this, I had decided to essentially "wing it" and try to reach the caps by just knowing the conversions. Doing this, I reached the hit and expertise cap. However, I was 20 points over the hit cap and 10 points over the expertise cap. The only critical strike rating that I lost was what I gained from reforging out of haste and mastery where applicable. I still lost around ~320 critical strike rating, though.
It will surely get better when Mists actually launches.