Saw that as well, and it looks interesting but not interesting enough for me to replace the TQC-14 that I've had for a few years. The TFC is 0.5" shorter and 1/3-lb lighter, neither are enough to make a real difference in most situations – the TQC + BH-30 LR inside its quiver bag already fits inside a carryon hard case (Peli 1510 / Peli 22" Elite / Storm im2500). I could see the 1/3-lb mattering on a long backpacking trip, but that's about it.
So to me, the difference comes down to the center column, and there are trade-offs either way. The center column adds ~11" of height at the cost of some stability. In fact, when I
tested it I was surprised that the magnitude of the effect of raising the center column wasn't as bad as I expected. I was trying various gear combos on two tripods, dropping a large sandbag from a fixed height for reproducible vibration which was stronger than the vibration I get from a shutter press, and seeing how long it took the vibrations to damp down at 10x Live View.
For a direct comparison of TQC-14 + BH-30 LR center column down vs. up, compared to the more robust TVC-33 + BH-55 LR combo, I was testing with the 1D X + 70-300L @ 300mm. With a properly balanced load, the TVC-33 damped in about ~1 s, the TQC-14 with the center column down damped in ~2 s, and the TQC-14 with the column up damped in ~4 s. Hanging a weight from the hook would reduce that time, and a wider lens would show less vibration effect. The most extreme case I tried was the 1D X with 100-400L @ 400mm on the TQC-14 with the center column fully raised and the camera+lens mounted to the BH-30 LR by the camera plate (i.e. a really unbalanced load, vs using the tripod collar as I'd normally do). In that case, the vibration took ~6 s to damp, meaning a 10 s self timer would have yielded a stable shot.
The trade off on the other side concerns ground level set. If you want to get the tripod as low to the ground as possible, with the TQC-14 you need to remove the center column, and that requires that you have the hex key for the set screws (it's a 1/8" hex, smaller than the standard 5/32" one for camera/lens plates - and I always have a 5/32" hex with me since the RRS modular base plate for the 1D X holds one). With the new TFC legs, you just splay them out and shoot.
I would not expect any stability difference between center column down and center column not present, and the TFC is the same height as the TQC with the center column down. So, really the choice is between having the ability to add 11" of height vs. the ability to
easily get the tripod at nearly ground level.
Personally, I don't regularly extend the center column of my TQC-14, but I do on occasion and it's worked fine in those cases. OTOH, I usually find that the fully retraced legs allow me to get close enough to the ground for my shooting (and typically if I want the camera
really close to the ground...I just set it on the ground). So to answer your question about which I'd opt for if I were buying de novo, personally I'd go for the TQC-14 combo. For me it's just gravy that I don't have to spend any more $$ to get it.
As a side note, if you get either of them the RRS quiver bag (TQB-47 for the travel combo) is a great bag and a perfect fit.