I have a Classic, a Classic Ghost, and a Sport. I have retired the Sport model because I took about two feet of skin off the right side of my noggin the last time I used it. The problem was me, though, not the razor. When I feel rushed I tend to try to move the razor faster and the Sport accomodated me on that day and that was the problem. I find that with the Classic/Ghost I am not able to generate that kind of speed.
When Walgreen's had the sale on HB I went and bought my local out of triples with the little face shaver handle (sux, I hate it, but it came with the carts). I've been using the triples for some time now and really like them. Before those I also used the Sensor twins and I like them a lot, too. When/if I run out of the HB3s I will definitely go back to the Sensors.
Have also tried a Personna cart a long time ago. Didn't get a very good shave with them, either. I think they were the Tri-Flex which is a triple.