Audio Note Step up transformers

Any one have experienced w/ Audio Note Step up transformers ? how are they ?
I have owned an Audio Note AN-S2, and I have used an AN-S4. The S2 was an older unit and was good, but not great IMHO. The S4 was a more recent unit and was very, very good. Much more detailed and coherent.

Neither was as good as the Choir Audio SUT-H, to my ears. But I have not heard the AN-S8, which is regarded to be a fantastic SUT. But it should be, considering the price.
I tried the AN-S2, but prefer the K&K that I built. And this was with an AN Soro SE Phono, AN AZ3 speakers, AN CD2, AN cables, and my home built Teres. I would like to try one of the higher AN SUT, but the cost has precluded me getting one.
AN step up are kinda pricey!! that the reason why am asking around how these are. Thank to those who replied