When I first saw this radio in a UK Ham publication, some years ago, I knew I had to get one.
In 2014, I did and installed it in my Toyota Hilux utility, having a remote head meant that I could install all the important bits out of the way under the rear passengers seats at the back of the vehicle and run a couple of control cables to the head unit, installed just above the centre console.
Being dual-band, this radio was right up my alley for local stuff and repeaters on VHF and National system stuff on UHF, with a wee bit of simplex stuff thrown in as well.
Apparently the TX audio from this radio is quite large (not distorted though), with a lot of contacts commenting that the radio puts out a very good but loud audio signal, I've learned to hold the mic away from my mouth just a bit further with this radio.
The manual is well laid out and the radio is very intuitive to program, I think it took me 20 minutes to set up all of the various frequencies, splits and CTCSS tones, it also has alpha-numeric naming of frequencies.
I really like this radio and I'm extremely pleased with it's performance, I wanted a radio that wasn't from the "Big 3" and this radio certainly delivered.
I had the DR-620T and liked how well that rig performed, except for the out of band intermod in heavy strong RF congested areas, like metros. From what I've seen from the newer DR-635T, it's the RX fix to that. Much tighter intermod rejection. Other than that, I didn't see the difference to the DR-620T. Good perky TX audio, and like pretty much most Alincos, maybe too much TX audio. Easy enough to adjust, but there's two POT's for that, DEV V for VHF and DEV U for UHF. (Just be sure that you have a deviation meter for this, or something else for audio measurements.) Good, perky, RX audio as well. One minus? On cold weather days below freezing, the UHF side drops its Squelch, until the rig warms up. Don't bother getting the Digital board, since it doesn't seem to be compatible with any format out there. Other than that, a nice alternative to Icom, Yaesu, and Kenwood.