I'm so glad to still have two old RO systems on board. Standard film tubes (cheap), Easy to work on Cat pumps, hoses, valves & salt detectors. It is hard to imagine newer RO systems to be considered improved. Maintenance cost are more, no back-up (manual) operation available and purchase cost are higher. Nothing beats our 25 year old Rich RO. Good luck with yours.
i have an older sea recovery 600gpd (late 90s early 00s) which is manually operated. I haven't had any issues with it what so ever. The membranes are also generic size which is great. I try to stay clear of equipment like this that requires proprietary consumable parts. Anyway, i havne't had any problems with my sea recovery.
Talk to Reverse Osmosis in Fort Lauderdale. They're a good company to deal with and good people. They may advise you what other membranes will work with your system...... On the other hand, as much time as it sounds like you spend in the Bahamas, $1200 in membranes will pay for themselves pretty quickly compared to buying water at $0.20- $0.50 a gallon