If you are smaller than 6'2" go with the 2" for sure. Even my 6+ buddies feel secure in 2" straps. I have standard latches on mine. I never use the shoulder straps. They have to be tight to be safe (harnesses have no give, nor do they react). If they are loose at all it can cause serious injury due to the shock load/point impact on the body. If you use a full harness on the street simple things like changing the radio, hitting the lights, tuning the CB, and most important -> checking blind spots, all become a big chore. You know how a normal belt feels when it is sinched down, that is how a harness is supposed to be all of the time. I love having them though. I just can't commint myself to the uppers. I do wear them when I am on the freeway for longer periods, and when I am all out on dirt roads, but in the city it doesn't work for me. Part of it is assembling the friggin' mess. It isn't easy to palm 4 2" belts w/3 hooks and one latch. Some places will let you try them out on demo seats, or heck find an offroad fab shop that has a buggy outside and ask if they would mind you checking out the seat/belts.
just my .02, I am also only 5'6" 145# so that may be part of it too.
