You say that one shouldn't use Prism Polish on Strataglass? Is Prism a more aggressive polish than the IMAR? I've heard many people speak highly of Prism Polish.
Plus, I have a bottle of it right next to me and was planning on using it on my strata tomorrow.
There are two treatments for use on StrataGlass:
IMAR StrataGlass Protective Polish
IMAR StrataGlass Protective Cleaner
All I can say is we've seen LOTS (I do some consulting work for a very high end canvas shop) of destroyed Strataglass from folks using the wrong products such as Plexus, 210, Meguiar's and Pledge to name a few. I can't comment specifically on Prism other than to say USE WHAT THE MANUFACTURER RECOMMENDS!
Remember, Strataglass has a very thin optical enhancing film on it to reduce distortion and improve clarity. If you wear it away, what you do when using Plexus, or Megiuar's you now have lost the benefits of Strataglass and it's optical superiority that you paid for.
Feel free to use what you want but I have personally had lengthy conversations with our Strataglass rep and heard many "war" stories of destroyed Strataglass. I really put him to the mat on this and just know that Strataglass makes NO money of recommending IMAR. They recommend it because it's been thoroughly tested and proven safe. According to our rep they have tested multitudes of plastic polishes and claimed protectors however I did not get names.. They recommend IMAR to keep their reputation good. Seth, the guy who owns the business I consult for, gives (well really it's built into the price, every new dodger owner both IMAR products when they take delivery.!
Use the Protective Polish once or twice per season then follow up in-between with Protective cleaner. The Protective Polish will remove the water spots unless they are acid rain etching which you can do nothing about.
Strataglass has NO vested interest in IMAR they make ZERO money from recommending it. They have simply tested it and find it is the BEST product for their product. They recommend it because they want to uphold their reputation and wearing away the optical coating will not do that..
These windows are now 8 years old and have only been cared for with Strataglass approved products.
Ignore the child and focus on the 8 year old windows (photo taken 5/26/08)!!