There are a number of great Dive Propulsion Vehicles (DPVs) available. I personally love my Dive-X CUDA 400. If I had more loot when I bought my scooter, I’d probably have an 1150 just for the increased run time. I rarely use what I have, but when you’re trying to plan thirds, a CUDA 1150 sure gives you plenty of time. Then again, you should probbly just drag along a second CUDA 400. But I digress…
There are a lot of options when it comes to scooters, with different trade offs based on the money you’re willing to spend, the scooter size & weight, battery chemistry (NiMH, LiPro), and range desired.
Depending upon your application, some scooters may be entirely out of the running (e.g. a Dive X Sierra doesn’t provide you very much range, therefore isn’t a great cave scooter.)
The Tahoma Benchmark Tests are your best bet for raw data. Each year different scooters were tested, so if you’re trying to read up on all of them, you’ll have to read all three reports.
My recommendation would be to find a friend with the scooter you’re interested in diving, and dive it.
While I love my CUDA, everyone that spends $2500+ dollars on a tool loves the one they selected. So asking people which one is best isn’t going to yield you too much of a delta from simply looking at the scooter they purchased already.