Having owned 3 different watermakers on 2 different boats, I think I can speak from experience.
The first one was a very used PowerSurvivor 35. It lasted for a couple of years while cruising Mexico
, with a couple of breakdowns. They were because of poor design and just being old imho.
We replaced the 35 with a used PowerSurvivor 80 which we purchased from a fellow cruiser. It was a much improved design and gave us no trouble up to the time we sold the boat.
boat came with a Spectra 180. The only problem I have had was of my own neglect, winter freeze damage. The design of the Clark pump is such that when freezing occurs, the only thing which breaks is a hollow glass piston rod. I replaced it without any further problems and I moved the installation
to below the waterline in the middle of the boat so it couldn't happen again! It is by far the best one of the lot, having owned it for ten years and I wouldn't hesitate to buy another Spectra.
I've never used any chemicals to pickle it; I just flip a ball valve and it sucks up its own product water
. After about 20 seconds of that I just shut it off. That procedure is good for at least 6 months in the Pacific Northwest
. Others have disagreed with that operation, but it works for me.