Hey toyotaboy,
We are new to gun dogs but we have a pair of 18 month old GSP's
Chronos (my name sake) seen here is a natural retreiver and will happily swim 50m or so out into a dam or the ocean to retrieve a ball or Dokken decoy but being new to hunting with dogs we are yet to truely test him in the field.

His litter mate shown here is a fair bit bigger and seems more of an indicating dog, less driven to retrieve or swim

As I said we are we to gun dogs so some aspects of their training has been lacking. They're happy to do most things we command but when together their competitiveness interferes with their obedience.
While a bit bigger than your old girl the GSP is a similar dog to the Hungarian vizsler and a size smaller than a Weimaraner, our GSP's are around 30kg and get through about 500gr of meat and cooked veges or rice or canned food plus 2 cups of dry food a day
We execise them for about an hour every two days and they spend most of the time inside when were home.
They do get a bit spoiled as is natural but have a great nature and will always greet you with gusto
Chronos