[Patrick]

I used the 1515 2.5d on 5s 4900's, then went to 4s 4900's with a 1515 1y (2200kv), kept the same gearing and could hardly notice any difference on the track. Didn't even need time to get used to it or change driving style. I haven't used the castle 2200, but I guess it would be almost the same.