High End Isolation - HRS, SRA, Active platforms

I would appreciate any opinions on cost-no-object isolation strategies. I have highlighted several in the title, but would appreciate any others which may be lesser known and underappreciated.

Please state whether you have first-hand experience with the product. Very important if you went from one product to another due to an improvement.

Also, please disclose if you are a dealer, distributor, or representative for a product. I think dealers have valuable information since they are enthusiasts that typically choose products that are most enjoyable.

Thanks
Rob