well the results and opinions on the matter are way to inconsistant for me to listen to anyone,...no offense...i think the only way to be fair is for everyone to do their own speed test and decide for themselves if it should be enabled or disabled....my results are below for those interested...and as for me im leaving mine enabled...

disabled 645.3 kbps
enabled 932.1 kbps

and i conducted my tests at www.mobilespeedtest.com
also i live in indianapolis, indiana if that matters...