Anyone uses FM Acoustics 155 Preamp

I am considering the FM Acoustics "resolution series" 155 preamp. My power amp is Passlabs Aleph 1.2 monos. Speakers are B&W 801 & 802s. I need to know if anyone using this fine swiss component has any advise for me. I really cannot afford the 255 which is a fully input to output differentially balanced unit and seems to me that the price/preformance ratio is good on this component though it is unbalanced input to output. Your recommendations will be highly appreciated.
FM Acoustics! Lucky you. What advice R U seeking?

Having only auditioned FM, I don't know if I qualify to post-- but here goes. I listened to, and loved, a full FM set driving Tannoy 12s (150 amps, I THINK your pre). Transparency, speed, and accuracy: top-notch, IMO stretching the speaker's limits -- or those of my cdp. HOWEVER, the sound was "different" from what I was used to, even on very familiar matl. It felt like I had more time to listen to small details and nuances in the sound, either harmonics (classical) or touches in the production (rock) -- e.g. discovering that what was a one-note electric guitar sound falling to the background actually changed note as it fell to the b/ground...etc.

Remember, this was a full FM rig; I assume the pre will mate well with yr Alephs, but cannot be sure.

FM Acoustics is reputed to "start where others peak", i.e., their entry-level allegedly compares with others' top of the line -- this includes pricing, too! On the latter, I assume you have listened to this unit? Can you do so with the Alephs? Just to avoid unnecessary investment!

Oooops, posted wrong models. Resolution 266 pre, Res. 411 power, was the combo I listened to. Sorry.