There is no need to upgrade your intercooler if:
1. You're not going to run a tune
2. You're not going to track your car
3. You live in a climate where summer daytime outside temperatures average below 85 degrees F.
As for which one to choose, I personally experienced fitment and quality issues with Forge, so just because something cost more doesn't necessarily mean it's better. From talking to other forum members, other brands have the same issues. Sure they advertise plug and play, but when you go to install it, it's a PITA.
So which one to choose? I recommend that you do your own research. Brands that have been tested by race teams should be in your top tier. As for plugs by forum members, take it with a grain of salt unless they are avid racers or track junkies.
2011 E90 M3 ZCP/AW/Ohlins R&T