Speaking from experience with the HTP kit...
Underengine piping is a pain in the dick to work on. You really have to have skinny arms and small hands to tighten the hot pipe properly since the downpipe will be in the way.
You have to dismantle the cold pipe for several maintenance procedures in the car, then when reassembled you need to do a proper boost leak test because of how much the piping can shift which can potentially leak. I used to religiously boost leak test the car every month and I would constantly find leaks, I even replaced all the tbolt clamps and added support brackets with no improvement.
With the kit, changing plugs and removing the HPFP for cleaning was easy. Yes the cleaner engine bay is nice. Overall the piping is inconvenient. I ended up going back to a TMIC after having the front mount for almost 5 years and I'm much happier now.
If you do have your heart set on a FMIC, I would suggest HTP for the underengine kit, and Cobb for the overengine piping. Both are quality piping that dont crush and they also have the least amount of couplers for less leaks. Stay the fuck away from Treadstone, their piping and tbolt clamps are garbage.