I am a recent 950 purchaser and was curious about any hiss, especially after talk regarding earlier versions. I checked my new 950 shortly after receiving it. It had some hiss the very first time I turned it on, and then I did a comparison to my THX-certified Onkyo. During the comparison I powered the 950 off and on two more times. By the end of the comparison I noted that the first-time-on, minor hiss of the 950 was gone. The Onkyo pre-outs, by comparison, have more noise than the 950 as the output is increased.
As to your 30-day trial expense, perhaps there is someone living not too far from you that has an Outlaw based system. While their sources and speakers may differ from the system you will put together, you could still (very carefully) put your ear to their speakers' tweeter(s) and try to judge if the 'noise floor' is acceptable to you. Or perhaps you can bring one speaker with you, one that you are 'used to.' A few hours for a drive-listen-drive experience may put your mind at ease.