I tried our wet-dry vac and found it to be slow going. Lots of stopping and dumping and re-starting.To me a net is a far better device - fast, simple, easy to store, and anyone can use it.
We went through a bunch of "pond" nets (sold by pond stores specific for ponds) in the beginning and were disappointed in the quality and longevity. They fell apart after several months of use.We finally switched to a pool net - a bit more expensive, but far more durable and the one we bought came with two interchangeable heads. One is flat and wide for bottom scooping and one is smaller for getting into tighter spaces. We store ours outside year round and the net has not degraded one bit in five years.
You won't get the fine debris with a net, but I'm not all that concerned about the fine stuff. And if you keep the leaves scooped, you'll get less fine debris build up as well. I would recommend a net over any kind of vacuum set up any day.