You don't require full power, or even full throttle in rush hour traffic, so null point (Unless you have mods and an engine that is leading to det problems in traffic)... My experience with my top mount is that it's been cool to the touch, even when the engine is stonking hot, after any cruise, and that's with a teeny tiny legacy scoop, and a VF39 with no heatsheilds.
My take on it, is only bother with one when it becomes necessary. Too many people slap em on a stock car cause they look good... which is totally pointless IMHO.
More than that i can't say, i've not had any experience with FMICs.
edit:
"I think i'll stay with the tmic, and use the money for a Link and a tune"
Good man! that's what I like to see.