Isinglass Cleaners and Polishes Question

[ConchPirate]

Our new (used) boat came with isinglass and a camper back with isinglass. The front and side curtains appear to have been used but not much. It seems they spent more time in the hold under the front berth - in South Florida (read that as hot or hotter and humid). So they felt a bit sticky and seemed like some yellowing had started. It was recommended that I use PLEXUS to clean and polish them which I did, and I must say they came out looking bright, clear and in great condition. BUT (there had to be a but!) The price jwas really steep, but I knew it would be less elsewhere.

Finally- the question. After price reviews show them all to be mostly comparable in price, has anyone found any real difference between the Plexus, Imar, 210, Plas X or other brands? Also, any difference between the one step cleaner/polisher/waxer and individual products for each of the steps?

I know it's an opinion type question(s), but it always helps to look at things from a different vantage point so to speak. TIA....