Wow, someone HAD to bring this up. Very touchy subject, my friend. I have them, but I can't remember the last time I wore them. I also tend to go with the "I'd rather get tossed and take my chances" point of reason. If you can call that "reason".
In my accident, I wasn't wearing them and came out okay. BUT... a really big BUT, I was in a residential neighborhood and the cop car was only going about 30mph. The hit was on the left front and I slid to the right side of my seat. HOWEVER, what kept me from flying OVER my windshield or through it, was my steering wheel. It got bent to crap, but I never felt it.
I let passengers, I don't have many, make the choice. They are bolted to the frame, so in a REALLY big hit, I'll be strapped in nice and tight, so the fiberglass chunks can slice through my skinny ass. Of course, if I get tossed out, with my luck, a nice old oak will be waiting for me or most certainly, the asphalt.
These are home built cars. They will only be safe to a very small degree. You learn to live with it and roll the dice. Only YOU can make the choice of wearing belts.