Opinions on Quicksilver Valve Linestage Preamp

Anyone with first hand experience with is tube preamp? Considering this preamp as a possible upgrade from my NAD C165BEE but I’d like to be sure that it’ll be a real upgrade. I honestly think the NAD piece sounds quite decent but hear too much about how a tube preamp will add to the musicality, etc. FWIW, they are both priced at $1K mark. It’ll be feeding my hybrid Vincent SP331 amp and the specs suggest they should be a good match.

Edited to add one more option in that general price range: Sonic Frontiers Pre 1L Tube Preamp .

I own the the Quicksilver and I like it . The only warning is that it’s very basic. No mono or balance controls,so if you need these features you should look at something else. If you don’t need those features then it is a true bargain! BTW,all my gear is QS and I've never had any problem,the stuff is built to last.
Love love my QS 6922-based line stage and listen to it multiple hours a day 365 a year w/o issues. I've also owned the 165BEE (nice piece as well), and I think the QS is the better of the two. 
Thanks for the input. Both of these components are very reasonably priced in the used market and seem like great opportunities to jump in to explore a tube preamplifier in the system. QS tube amplifiers certainly have a great reputation.
There's no such thing as a Sonic Frontiers Pre 1L. Are you sure its not an SFL1? If it's an SFL1, I would definitely take it over the NAD or QS.
The SF model is advertised as an Anthem brand supposedly "made by" SF. Not sure what that means.
Anthem is a different brand. It was owned by SF but the products are completely different. I would go with the QS over an Anthem. 
Owned the QS and the 165BEE.  I am going to say a QS will sound different but not necessarily better.  I did not have the 6922 version, the older one was 12ax7 based if I recall and it was nice but not the smoothest upper mids/lower treble.  I replaced it with a AES/Cary AE3 DJH which was better bigly.
If you want to get a taste of tubes without spending much, there is a Croft Acoustics Micro 25 listed here for $540. It looks like a real bargain! Here is some info on it . Grab it before someone else does !