I’ve had a Hydra for about 4 years now and really like it. I generally run the cooling water through the stainless steel immersion chiller that it replaced first, putting it in a bucket of ice. I brewed a cream ale two days ago and cooled it from boiling to 68 degrees in 12 minutes.
When I changed to electric brewing, I called JaDeD and asked about using the Hydra, and wound up buying an “electric chair” from them that raises the chiller up above the heating element - still works fine.
I heard some rumors that JaDeD will be offering a stainless steel Hydra - check with them if you think you might want to go that route.