Yes, I have heard AND demoed the aria wt350LS (non XL) in my local sellers store and my home! They really do pass the sound of the ANY tube to the speakers, but power cords make a HUGE difference too. keep $500 back for a pair of cords (unsure of brand used). I did not choose to buy the arias since my preamp would not drive the LS version and extra shipping and salesman's efforts were necessary just to see how the HS version would go with my Linn Kairn. i felt that this caliber of amp needed a preamp like a SA-11 like you have to do justice. A krell KCT is all i got to hear them with and the arias pretty much passed the analytcal sound of it right through to the speakers unfortunately (i hate analytical sounding stuff-the way krells can be). i ended up going with a Klimax twin which really goes with my linn stuff but am still UNSURE if it was the wiser choice. am using BW N803's currently. in the store i heard the arias with 800's & the KCT. i think all the b&w Naut's are a bit analytical too which keeps me from really knowing how good the aria's sound. the arias seem to be really transparent. do us all a big favor and try them with your sa-11 and let us all know how it goes. I will probably be looking to these in the future when i have a real (SA-11) tube preamp, or when i can afford mike's new aria preamp that should be appearing shortly. i wonder if the wt100XL version may be a better choice than the wt350standard if you can get by with 100 watts? i can't believe i turned down a LIFETIME TRANSFERABLE warranty over Linn's 2 year labor 3 year parts! the k-twin is really laid back smooth magical sense of ease yet articulate stuff, but i assure you i paid INFULL for it and didn't get much increase in listening volume. (maybe i did get more volume but it is so much less noisy and less bass boomy than the Klout it does not SEEM like more power). about the arias though, all i can say is they really had sledghammer bass and lots of transparency. they really made tom petty's "you wreck me" on wildflowers rock like no tomorrow. no matter how much loud stuff was happening, you could still here all the softer background stuff. serious jazz was equally done justice too. am unsure of its tonal quality and sense of effortless ease (non-analyticalness) due to the dang KCT. sorry i can't be of any more help than this.
That's my 2 cents.