hobbywing all the way, huge power and seems to be reliable, ive bashed mine pretty hard, and ran on 6s all the time without breaking a sweat. rarely does my esc get over 100, the hottest its been is only 115-120 (geared 44/18, crazy speed). the motor has gotten up to 140-145 during some longer runs, no biggie. i have the xerun (way better than ezrun) 150A with the 2000kv motor. heck you could get 2 hobbywing esc's or full systems for pretty much the price of one tekin and have a spare incase something happens. there is absolutely no way the tekin is twice as good as the xerun. oh and a little tip on the xerun esc, take it apart and replace that tape stuff they use to attatch the heatsink with some good quality thermal grease. i just did speed runs on 6s (probably geared for 80 or so) and the esc was still only 90-95 after running it quite a while, all high speed. plus the HW program card is great, you can change the settings in no time. thats one thing that i hate about castle. lots of options with castle link, but who the hell (exept maybe pros) wants to bring their laptop everywhere and spend a bunch of time setting the esc?