I carry the SWAT Tourniquet because I think I could apply it one-handed to an upper extremity on myself a little more easily, and I can also use it as a compression wrap if I just need something to hold a bandage in place with pressure. I make up for the size savings on deeper trips by carrying a couple ounces of iodine and a syringe for flushing wounds, however.
EMTI/AEMT for almost a decade with wilderness certs and 5+ years of EMS education, years of ER/ICU work, SAR, ski patrol, and international experience here. Be cautious taking advice from people spouting about, "oh my god what if I trip and blow my arm off and am bleeding to death miles from help," which is something that maybe, if you are a dumbass can happen. The reality is that if you are responsible, use good risk management , and have situational awareness, the vast majority of care you will render in the field will deal with mild musculoskeletal injury and minor cuts and abrasions. Don't miss 98% of you opportunities to help to catch the bad 2%. I cannot tell you how many tactical morons I have encountered that have tourniquets, IVs (and no clue how to use them), hemostats (TO CLAMP THAT ARTERY LIKE IN BLACKHAWK DOOOOWN) but are in need of help because they don't have basic shit to treat their blisters, scrapes, diarrhea, etc. If you pack your kit right you can handle the 2% with the gear to handle the 98% too.