Jafant...
Definitely not First Watt. The F6 offers the most power into 4 ohms which is 50 watts per channel which...may not be enough for your 2.7's. You already know how quickly I moved from my FW M2 amp to the Pass X150.5.
Like I've mentioned my listening level is very conservative and I very nearly purchased a new Pass 30.8 which offered 60 watts into my 4 ohm Thiels, but another X150.5 came up and I jumped on it. Based on my history I think the 30.8 would have sufficed but then...mo' power in reserve is mo' better almost all the time. I did not audition the M2 nor the X150.5 prior to purchase, either. I purchased them based upon threads here, reviews, and word of mouth.