We've had 2 Japax and 3 Sodick units in the shop. The Japax were not submersible tables and the Sodick are. There are good and bads in either case. The real problem is the maintainence to keep the machine in tolerance. The current 2 Sodicks are older and we are looking at replacements in the near future. Parts are getting harder to find. We currently have one down waiting for a new/ used computer.
Auto threading is an option you should look at. The wire always breaks when you just leave to do something else.
Filtration of the water and resin are critical and we change filters about once a week. We added a pre filter to remove the larger particles before the return water gets to the real filters, it has helped.
Also look at whether the return water is dumped into the main tank, thus mixing with the filtered water, bad design as the Sodicks we have do that, while the Japax had separate tanks for the return water and the filtered water.