I have two DNT optics. Both are the Thermnight TNC335R models. I use them to hunt coyotes (not legal to hunt big game with it in my state.) So far so good but I've only had them for 10 months. I liked the first one enough to buy another before the price increases with the tariff stuff earlier this year. I don't know anything about their other thermals (Ex. Hydra) but if they have the same core and algo they should be good too. My thermnight smokes my two iray 384 scopes from a sensitivity perspective, but Iray has come out with new stuff since the original rl25 I bought so that may be a bad comparison but they are both 384 cores I believe and there is no comparison while the Iray cost me a lot more. The surprising thing is that often the 384 core DNT picks up stuff my pulsar helion 2 xp50 pro (684 core) does not so it seems at times that it is more sensitive but I haven't looked up the specs in a long time. Prior to owning the DNT thermnight I had strong opinions about Pulsar's algo smoking the Iray models I owned as far as sensitivity/flaring/etc.... That hasn't been the case with this DNT optic and I am sure Iray's newer stuff is way better too.
The thermnight model is cool with the various features but also clunky. Ex. focusing the thermal is tough with gloves on and even without gloves on because all the lenses are packed together tightly and that lens just isn't easy to get your hand over and onto. I don't mess with the focusing on the thermal much as a result but sometimes you have to when you are stretching a shot. Focusing the digital image is easy as there is a bit of a lever and it is on top.
Daytime use of the digital part is ok. I thought it would be nicer but there is ZERO comparison to a traditional scope of almost any quality... the image is just not as clear and I don't like it as much. However, using it at night to get a better identification of critters is cool and works well most of the time. Not so good with thick hunting conditions with the IR light hitting foliage/etc..., but works really well out in the open. The other knock is there are a lot of buttons on the thing with both Digital and Thermal lenses and sometimes I hit the wrong button when I have gloves on but I've gotten better navigating all the choices.
DNT has been great to work with too. I lost the rubber eye piece hunting in the woods and they sent me a new one free of charge. How excellent is that!!! I haven't had to contact them for any issues with the scope.
The ballistics app works well but I haven't stretched shooting beyond about 400 yards at night so can't say how accurate it is beyond that.