They are very, very, very good. I have 2 rifles using their lowers, 1 being a complete lower purchased from them and a stripped lower I used to build a dedicated 22lr platform. Their prices are excellent as well, but it is their customer service which shines the most. They have done 2 suppressor transfers for me.
FREE. Actually, it cost me $10 total for the $5.00 background check. They received my 45 Osprey and my YHM mite on a F3 from Major Malfunction, and upon receipt, charged me $5.00. They even do this for normal FFL transfers. Nathan and Darren are great to deal with, and take time to answer any questions you may have. Pics of said rifles:
Bottom suppressors were both transferred by TM, top rifle is the TM complete lower, changed the stock and grip.
This is my 22 using the TM stripped lower with engraving post anodization