I agree that both are good choices for sure - it will really come down to how you plan to use it. Both will hold a RTT no problem, but I went with the Front Runner (3 times: JKU, 4R, and Tundra) for the increased versatility of the accessories: the RTT mounts, the awning mounts, the shovel mounts, etc. Any of those can go on/off relatively easily (as I am sure then can on the Gobi, but I don't have first-hand with that) - so if you want to uplift for a trip and not keep everything on all the time, it is a great option. The all aluminum construction is great - I have scratched them up fairly well and no rusting issues.
Again, you can't go wrong with either
Ryan