Front mounts can be bigger, have better cooling capacity, and are less effected by heat soak.
But I agree, for a stock turbo and only 300hp the added cooling capacity isn't even worth the money to install the FMIC. You really should aproach the capacity of your top mount before it's worth switching.
On the other hand... losing that retarted snout might just make an FMIC worth it.
jus kiddin'