This is a really interesting thread. Took me two sittings to read it all. I am new to car computers but not car audio. I have been installing professionally for almost 16 years. I build custom show/competition vehicles and I am an IASCA judge but no longer do any judging. Like I said I know very little about computers but I have two show cars here that I am going to install computers in both. I want to thank the guys that have offered some very good points on why to use a computer. One of my major concerns is SQ. I am still concerned but I believe I am going to use a very good sound card and run it into a good 1/3rd octave eq...hope it works.
There are a couple of things I would like to add to. First is the RTA does not have to be flat to give a score. Anyone that is serious about SQ needs to use a RTA to tune their car. The RTA redout does need to be flat it needs to have no breaks in the frequency response. There can not be big jumps in frequencies. That will kill your RTA score but also overall SQ. The car should be tuned using a combination of ear and RTA.
Another issue talked about is judging. Judging is very biased. Alot of comps use judges that have 10 minutes worth of experience in car audio and none in judging. What they think sounds good is not often what the "norm" is. IASCA tried to solve this problem with a disc that takes away alot of individual opinion. It worked so so. The big problem with competion is the judges.
Cables are not a scam. High end cables do work better then the 2 dollar stuff off the shelf of Radio Shack. But that is only if you are able to by them at the right price. Cables and accessories have a HUGE mark up especially at places like Circuit City and Best Buy. The quality is there and the product is worth using but at the right price.