The reason that I had gone to this combo when I had my 5spd were as follows:
1. The STi unit is much beefier than the USDM version and I was putting down enough power to make this a concern.
2. I had been thru the aftermarket excedy full face unit as well as several other clutches. The heavier duty of which held the power but were a nightmare to drive on a daily basis. On the other end the full face units I was tearing thru. This was a good compromise of both.
3. Cost. Very inexspensive and at the time that was a concern.
4. Availability. There was one in the shop.
I really liked the feel and holding power of the STi unit. I of course eventually went to the 6 spd and still use the stock STi unit with that. This isn't for everybody, but it worked well for my situation. Thanks.