Actually, the 9.5 would not have been a Clinton. As to the question at hand, you asked for an opinion, so that's what you will get. The Clinton is noisy, vibrates and hot & stinky. But they do run reasonably well. Yes, the powerhead is air cooled, but the exhaust is water cooled by a very chintzy water pump that fails often. If that happens, it will continue to run, but the heat travels upward to the powerhead and that overheats also. Being air cooled, of course air is fan-forced down over the powerhead, just like a lawn mower. Nothing wrong with that, except if you plan to run it in salt water, that is salt air being blown over it. Last I heard, parts were still available from the old Clinton employees.
Summing up, the Clinton is a cheaply built motor, built to sell at a cheap price. And they did sell a lot of them. And they usually ran.