Yagi's are great antenna's, and especially so if you're on a mast. Going thru wood decking and asphalt cuts the signal strength roughly in half though, which may explain why I've been unsuccessful with multiple TV's off the same antenna.
For my shortest coax run, ~30 feet, I'm using a ClearStream 2V, which is the old version of what I linked above. The VHF element on this is the long horizontal bar at the top, and our NBC is on VHF. I've got this fed from the antenna down the wall with compression fittings on RG11 quad shield, but the signal. This works great, but if I switch it to the other TV, which is a bit more than twice the distance of RG11 feeder coax in the attic, then no go on VHF and inconsistent UHF performance except on clear days.
For that TV Is used a ClearStream 5 , which is freaking huge and dedicated to VHF, along with a combiner to join it to a single DB2, and everything comes in perfectly. This single little bow-tie style pulls in everything, including channels 50 or 60 miles away on the back side of the antenna. I can't imagine what type of signal the double or quad gang of these little guys would pull down, but I'd imagine signal strength would be a non-issue, well on UHF anyway.
All of this stuff is very prone to attic gremlins, stuff that makes no sense whatsoever has dramatic impacts. For instance, I combined the above two setup antennas with 3' RG11 coax and got nothing, but replaced just these two cables that tie the antennas to the combiner with RG6 cables and all is working great. Attic mounting is tricky and very different in each house I've been in. What works in one, doesn't mean anything for just across the street.