last year I ran AE RC8T w/OS25xz, wasn't all that happy with the durability of the os and previous os engines I had in the past. I am looking at the Orion mills for 2011. I was thinking the .21abi 7 port or the .24abi 5+2 port motors. These both are quite expensive mills. Please give me feedback on ave. run times and comments on which to use and why. Please help me make up my mind. I generally race every weekend April to Nov.

Thanks in advance.