I have a LBT6094A and LBT6094A-SLICK, both "Gen II" for swimmer-cut plates. I recently picked up the Crye AVS.
The LBT6094 is a classic, but IMO is outdated when compared against the newer Crye stuff.
It's comfortable, comes with MOLLE everywhere, has routing cables for hydration and comms cables, and the integrated kangaroo pouch as well as MBITR pouches are a plus (note that I don't even take full advantage of the comms stuff since I don't operate). I love the kangaroo pouch and it also has an admin pouch built in the top. The Gen II front plate bag fits my swimmer-cut plate like a glove. It also has integrated and remove able shoulder pads.
That said, after trying the AVS, I'm not sure I can live without the skeletal cummerbund. I tried using the Crye cummerbund on the 6094 but it doesn't maintain its form since it can't fasten to anything inside the loop in the rear platebag; if it did, it would be an awesome combo. The AVS also allows for more customization, but it does come at a cost. You have to buy shoulder pads separate. Both carriers require extra stuff to make full use of the kangaroo pouch (I like the S&S Precision GRT kangaroo pouch in the LBT, which won't really work in the AVS.
The AVS feels every bit as sturdy as the LBT, and it has an impressive use of Velcro for fastening different things to the carrier, such as side plate pouches and mag pouches for the front plate bag. As much as I hate to say it as I love LBT, Crye's mag pouches are nicer and more uniformly constructed (I got a set of three LBT 762 pouches and they showed variation in the sizing; all three cost about as much as a Tyr Tactical triple 762 shingle and Crye MOLLE front panel, which show excellent construction.
I give the LBT a slight edge in comfort, but I haven't tried the Crye harness yet...I just have a plate carrier configuration for now...but that may really increase the comfort.
I would still choose the LBT6094 over most other carriers, but a lot of that is personal preference for using cool-guy stuff. It comes with a lot out of the box and you can count on their lifetime warranty. It's also ready to go with all of your existing MOLLE kit without needing extra pouches and panels like the AVS does.
Just my $.02 from a guy who has only used the LBT6094, Eagle Industries LE-type (forget the name), and the AVS.