The LDS that rents/sells them wanted $250 for the dpv specialty course before they'll rent you one, so he just bought it, figured how hard can it be to use, lol.... They are pretty simple, just on - off, pay attention to your depth and time, they run about 40 mins. He usually dives nitrox and at reef and top of the wall depths. He's quite happy with it. Buy an extra battery or 2 if you want to do multiple dives in a day, be carefull of the big O ring under the nose when changing batteries. You get no battery options, it's a Douglas Guardian 12-32 while it's a U1 designation, no one else makes it as an SLA, Torpedo modifies the terminals as well, cuts them off and solders wires on the stub. It's a 12V motor, so you have the high current draw that goes with that. Much less efficient use of a batter than 24V scooters. The Torpedo guy's dive buddy has a Dacor, I like it better as it uses the multi pitch prop and kort nozzle design that's so easy to get parts for and has a proven track record. Alas, it too is a 12V scooter, and is limited to purely rec diving. Slightly bigger battery than the torpedo, but on higher pitch, it's faster and burns about as long.
As far as choices, there are 3 models, offering slightly better speeds and/or burn times. All are within that $800 to $1100 range.
For my money, I'd up the pot a bit and go for a used/refurbed Mako for about $1400 .... Easily twice the scooter or more. Get NiMH batteries for it and use it for multiple dives or longer doubles dives.
Hope that helped,
Darlene