I have an 857D I run mobile and liked it so well I also have one I run in the shack as my primary radio. The only issue I have ever had is the screen size as I've aged and eyesite has begun to suffer. However, when armed with my reading glasses, I am good-to-go! I have ben running both since early 2000's without hitch or problem.
Noisy receiver but beyond that it is a good little rig and a great mobile.
For close to the same money you can buy a Kenwood TS-480SAT and get a better rig, but if you have to have the 2M/70cm the FT-857D is the way to go.
This is a great little rig that is versital in all uses. I have used it as a base, a mobile, and a portable. The menues are easy enogh to use and it is pretty operator friendly. All the controls are right up front and easy to access. The separating face is great for mobile and portable. Light weight and easy to pack for different types of operation. The only thing I find wrong with this rig is that it really gives no place to attach a good grounding wire. Other than that it is great. The same rig internally as the FT897. I recommend this rig to anyone stationary or active. A great small rig that does all I need since I am a fulltime RVer and need the space. My last rig was the FT901DM. Just too large for RVing. If I had to buy something different it be the FT897 or FT897D
I use the FT857D for 4 years now. Once blew the CW key input due to RFI - which is strange for a HF set. OK, I should not tune full power on 10m, but still no reason to die...
6m is terrible on this rig. The PA tends to oscillate very quickly and therefore I gave up on 6m. I use mainly CW and if you do that, an extra IF filter is a must. The IF bandwidth is otherwise far to wide. I bought a Inrad 300Hz filter and that really makes a difference. SSB is OK I guess. Made a couple of QSO's on phone but getting the modulation and processor settings right may take you some time with a friend on the other end to get things straightened out. And because of RFI (I use a end-fed aerial) the set has reset to factory settings a couple of times. For mobile use it is probably a great rig because of the size. For base use I would not recommend it...