Re: racing harness
I think any talk about belts should also include talk about the seat. You have to think of everything as a single system, including your helmet and head restraint if you use one.
For example, if I was tracking with a stock Viper seat, 6pt harnesses are a no brainer. Thinking that a 5th pt that has to attach up over the front of a stock seat is going to do anything for you is foolish.
I have a Sparco Pro2k I put in for track duty. Its different than a stock seat in that it forms a 'bucket' that angles my ass down and to the back of the car from my knees. I wish the stock seat did this too cause its much more comfortable for me. The Sparco also of course has a slot in the bottom for the 5th pt. which comes up right at my crotch and makes the shortest possible distance between the floor anchor and the camlock. Oh I also have TeamTechs which use a large triangular pelvic pad at the 5th attatchment pt. rather than just the plain 2" web neuter belt other setups use.
For me, I feel so secure when combining the seat and the angle its on with the tight, close fit of the 5pts that I don't see an advantage to going with 6pt setup. Although I've never been in an accident either, nor am I saying that 6pts aren't safer. Its just a matter of 'safe enough' for my comfort.
Seat angle is also critical to account for when you get a HANS. The angle of the yoke on your shoulders has to be matched to that of the seat, or else inappropriate pressure can be put on your sternum in an accident and end up breaking it.
Just thought I'd mention it. The stock Viper seat is a POS in my opinion though so I'd assume people swap them out.