Hi!
I bought an FT-4XR a few weeks ago. It is a basic dual-band FM HT, and does that well. The frequency ranges make it look very much like a Baofeng UV-5R type of radio (136-174 and 400-480 MHz RX, plus the broadcast FM receive). The Yaesu battery packs can be recharged in the drop-in chargers for the UV-5R, and UV-5R battery packs can be recharged in the FT-4XR's drop-in charger (also used with the FT-4VR, FT-25R, and FT-65R).
The speaker-mic is like those for Motorola low-end business and GMRS/FRS HTs - two pins, speaker audio on the larger 3.5mm socket, and a smaller gap between the two pins than with the two-pin speaker/mic connectors for many other HTs. It is a small radio, but doesn't feel "cheap". It seems like it can take a bit of a beating, more than I'd expect with a UV-5R.
The antenna connector on the HT is a male SMA, and worked fine with the same BNC adapter I use with my UV-5R. I have yet to try the antenna that came with the FT-4XR, which - by the way - is the same antenna that comes with the 2m FT-4VR.
Yaesu has a programming cable for the radio, SCU-35, that's not as obnoxiously priced as accessories for many other HTs at around $20, along with free software to program the radio. I also found that the M lead (mostly used with Motorola radios) from a programming cable set I already had:
https://www.amazon.com/KENMAX-Program-Programming-Talkies-Motorola/dp/B01466PL7U/
worked fine with the FT-4XR. In fact, the driver for the Yaesu SCU-35, for a Prolific chipset, also works fine with the KENMAX cable I have. If you prefer RT Systems, there is a programming package from them that supports the FT-4XR and 2m FT-4VR HTs. There is also a speaker/mic that is around $20-$25.
One advantage in the FT-4XR over the similar FT-65R (larger dual-band HT, but the internals are very similar to the FT-4XR, and by extension Baofeng UV-5Rs) is that the memory channels in the FT-4XR can accept independent transmit and receive frequencies. The receive and transmit frequencies don't have to be in the same band. Whether using a cross-band repeater or an FM satellite, the FT-4XR is easier to use with those systems than an FT-65R, whose memory channels can accept a receive frequency and an offset size/direction, where the offset size stays in the same band as the receive frequency.
This radio may not have the wide-band receiver like the older FT-60R or VX-3R, but the value of a wide-band receiver in an FM-only HT is diminishing with the march to digital voice in the non-ham spectrum. Even encrypting analog FM makes the wide-band receiver less useful. For just under $100, I'd go with the FT-4XR over the similarly-priced Alinco DJ-500T for a dual-band HT from one of the traditional manufacturers in that price range.
I have not disassembled my FT-4XR, but would be curious to see if it uses a transceiver-on-a-chip like the Baofeng radios. I would also like to see the inside of an FT-4VR, to see how similar it is to an FT-4XR. I wonder if these two radios are more similar on the inside, to help cut down on production costs in Yaesu's Chinese factory for these HTs. Yaesu requested that the FCC not post photos of the internals of these radios on its equipment authorization database, so I can't use that to answer my curiosity about the FT-4XR being similar to a UV-5R (other than I expect the FT-4XR would meet all techinical requirements in FCC Part 97). I may open mine up, but not today.
73!