TBS Crossfire is actually the first 868/915mhz product that was basically available from a "real" commercial company. 915mhz versions of OpenLRS predate it, but there were no "official" 915mhz versions of OpenLRS products.
TBS came out in 2015, and it saw limited usage, due to its high cost. at the time the original TX module was a small black box that connected to the trainer port of most r/c transmitters, and used PPM as its input. very quickly a JR style adapter and the advent of their serial based communication, known as CRSF protocol allowed it to work "better" with specific radios that used OpenTX as their firmware.
the second version of the transmitter module was still quite expensive, basicall 4x the price of a comparable frsky r9m module.
TBS originated in the r/c Drone world, so most of the first receivers were drone style, with primary communication being the crsf protocol with flight controllers. PWM adapters and PWM based receivers did start coming out.
not long after the FrSky r9m came out, TBS released a second generation of JR style module, labeled V2, and much more like the FrSky r9m module. the biggest change is that apparently TBS wanted to stay ahead of FrSky, so they dropped the price of the Module and most receivers. although not as inexpensive as the FrSky products, the price was now much more acceptable to a much larger audience, and that plus the perceived superiority of the TBS product. the Crossfire system offered two things that were "better". Lower latency, and dynamic power allocation. for most drone racing, the latency was a big driving factor. For r/c submarines, not so much.
so, for those keeping score: TBS crossfire is capable of PPM and CRSF input from the transmitter. there are two major revisions to the hardware, v1 and v2, with v2's primary goal to reduce cost. it started out as Drone only, but has grown into both drone and "wing" based receivers.
I did not buy any TBS Crossfire equipment until the first big drop in price. by then the failures of FrSky and the bugs were known quantities for most people, and like most long range drone flyers, i was basically pissed at FrSky for making a mess of r9. as soon as i could i bought a TBS v2 JR module, a Nano Diversity receiver and an 8 channel adapter for the receiver. I started testing the crossfire equipment in my trusty brüggen delta submersible, and immediately noticed that the dynamic power allocation did make a noticeable difference in the depth that the submarine could reach versus the r9 equipment.
I just recently added two more of the nano receivers and 6 channel PWM adapters for more testing. I am not 100% certain that the non diversity receivers offer the dynamic power allocation, so that is why i picked them up.
Unlike the FrSky products, there has been little to no problems with firmware bugs, there has been no major change to the protocol, and like most of the advanced systems, it provides telemetry. I do think that the telemetry in TBS Crossfire is skewed towards that which a Flight Controller would return, and is not as easy or wide spread as the S.port methodology that FrSky uses, but it is sufficient for most items, providing current, voltage, and quality of signal information.
One thing that TBS Crossfire V2 with its CRSF protocol did require at first was a relatively new OpenTX based radio, capable of handling a 400k bps serial transfer rate between the transmitter and the module. newer versions of the protocol have made that adjustable, so "lesser" radios can use the protocol. They have also come out with a nano style case so that you can use it with the newer FrSky and Radiomaster radios that use the Nano/Lite style module socket.
The biggest problem i have with TBS now is basic availability. most website store fronts that carry the product are out of stock more often than not, including TBS's own website. not sure exactly why.
One more thing. the original TBS Crossifre TX module has a max power output of 2w. the Micro TX (the basic JR and Lite/Nano style transmitter modules) have a max power output of 1w