john1;
Thank you for posting this topic. Hospital grade outlets are certainly better than standard house outlets. I have spent a lot of time evaluating many but not all audio-grade outlets. I believe you will hear a further improvement in your system with one of these outlets.
Cleeds brings up one good approach which is to buy an outlet with a money back policy. Another approach is to buy a used outlet here on Audiogon - currently listed is a Furutech GTX-R. This is a very good outlet. Buying with a money back policy I would buy a Synergistic Research Black outlet if my maximum budget is $150.00. I do prefer the Black over the GTX-R, but both will sound good. The best "deal" is to buy a Synergistic Research Blue outlet for $285.00 and get a free Blue fuse. Put the fuse in your DAC, Pre amp, or amp. If you do not like them return them both for a refund. This deal expires at Synergistic Research sellers December 31.
How good is the Synergistic Research Blue outlet? After putting one in my Mother's system, she took a listen and gave me a very nice kiss on the cheek. She is a very astute audiophile!
David Pritchard