I had a discussion with sailing friends and a West Marine
sailsperson one time and if I were to buy an inflatable I'd opt for an automatically inflatable PFD
because if you were wearing an inflatable that was manually operated and you were tossed or knocked in the water you may not be conscious enough to inflate it. Since I get wet frequently and wearing an automatic inflatable might cause me to keep recharging it at $20 to $40 each time. Too expensive! So, I opt for the old buoyancy aids but more often don't wear one unless I leave the bay. When I leave the bay I wear a tether most the time.
During our training course we require positive buoyancy aids (PFDs). Since we cannot afford to recharge the student's PFDs each time they go out on the water in small dinghies we use a water ski type PFD
that is fairly comfortable and lets the user reach without too much hindrance.