there are ups and downs about both intercoolers.
top mount is good for stock boost.
has a short route and has a small volume so you get boost quickly.
downside is that it's on top of your engine and it gets hot. hot air = less bang = less horsepower.
so fitting a large front mounted intercooler will fix the heat soak but adds length to the system therefor the boost will come on a bit slower. but then again the cold air you get gives a bit more bang so it's all down to what you prefer. do you want a quick response or a bit more power?
but once you start upgrading the engine, turbo, up the boost then there is almost no way around a FMIC because the small TMIC will struggle.
there are other TMIC's you can get (arc, rx7) but the arc is wicked expensive and the rx7 intercooler isn't really my taste)
hope this helps