Not familiar with TYT's digital offerings, I took a look a quick look at there website. The only reference I could find was to DMR. I didn't see any mention of dPMR. HAM enthusiasts use of DMR seems to be picking up speed rapidly in many areas of the U.S. I picked up a CS700 from Connect Systems a few months ago and really enjoy it. I have more distant QSOs than local ones using DMR and there are several DMR repeaters in my area of California. I don't know of any dPMR repeaters. In any case, another vendor "in the pool" wouldn't necessarily be a bad thing whether DMR or dPMR. I think the affordably priced CS700 has allowed a lot of HAMs to get their feet wet with DMR.
I saw your link showing the TYT dual band dPMR. I didn't see that on their website. A decent radio with those specs shows promise. I haven't seen one that is dual band, just single band. I wonder if it does analog as well. It's hard to tell as there is little information on the radio.
Your understanding of dPMR vs. DMR is the same as mine. dPMR uses FDMA while DMR uses TDMA. Unfortunately, Repeaterbook doesn't show any NXDN repeaters in California on which to test these. For the price, it would be fun to try though.
If you've got an itch to try DMR and there is a suitable repeater in your area, give a CS700 a try. You could get a radio, programming cable and software delivered to you in the $200+ range.
Two similar radios operating in simplex might be able to achieve a few miles depending upon terrain, altitude and antennas. Naturally, you mileage may vary. I can do a little bit better inside my house with a DMR HT than an analog one. I attribute that to the error correction that takes place with DMR, giving it a bit of an advantage when the signal starts to get weaker. However, if you have no repeater and you've got no one in range to do simplex, you've got a battery powered paper weight.
Radiosfiction has some good reviews up of DPMR and watch out for the fact that none of the DPMR radios play together at all in digital mode.
They are also not compatible with Nexedge or IDAS.
Here is Radiofictions site. Radiosification
Apparently he reviews a new one from Kirisun as well as earlier reviews of the Kirisun 780 DPMR radios. He also has a youtube channel here with video showing testing and such he did with radios.