Also, talking about seatbelt cutters and rescue tools... There are clearly many different options available. Webbing can be cut efficiently with a sharp knife, scissors, shears, specialized seatbelt cutters - but some may work better than others in a specific scenario.

Rescuing somebody else trapped in a vehicle for instance is not the same as attempting to do a self-rescue if you happen to be the victim yourself. IME a sturdy fixed blade knife makes a very good egress tool in a pinch. Some models like the Gerber LMF II have specific features that make them particularly effective for that sort of work. The Glock field knife and many other blades of the "sharpened prybar" variety work well, too. Robust enough to force open a car door if needed, and the point (or a glass breaker pommel if available) can be used to break a windshield. Plus there's always the sharp edge for cutting webbing and such.

A self-rescue scenario on the other hand is a different matter. You might get knocked unconscious or hurt pretty badly. People react differently to that sort of thing so it's good knowing (through training or previous experience) how you react under real stress. I use my EDC folding knife so often that it's really become an extension of my arm. I also keep a seatbelt cutter in the car, but honestly speaking I've not deployed it very often for any real purpose and I don't find it all that intuitive to use. It might be safer to use than a knife, but I'm not absolutely sure how well it would work for me under stress when seconds count.

Either way, some types of seatbelt cutters don't seem too practical if you have to use them one-handed. This could be a concern if one of your hands is injured or trapped somehow. In any case, getting caught in a bad vehicle crash is going to be a cr@pshoot. If the adrenaline kicks in quickly enough it might help initially to supress the pain and give you a momentary boost, unfortunately at the cost of fine motor skills. So little things like opening a folding safety cutter blade could become a problem.