I bought one a couple of months ago, it is reasonably well made, throws a lot of light but it is clunky to hand hold underwater, so I modified it for umbilical and canister use and mounted it in a goodman handle, Modifying the XTAR D-35 for Cannister Attachment.
This works better than the hand hold version by far, but this modification is not for the faint of heart and a lathe is a necessity. Yesterday I took it down to 40 m and compared it with the new light I just built, SST90 and custom driver and the new light blew it out of the water. So all things considered, I'd say the D-35 is a decent light, but for that price one should be able to do better. I'm taking it cave diving at the end of this month, so we'll see how it works in the caves. On thing though, if you buy it and throw it in your gear bag with batteries installed, be careful the ring switch can easily be turned on by accident and roast everything around it. I leave it disconnected from the battery pack until I am ready to dive. Underwater the switch is great, but the manufacturer should have created some kind of locking mechanism when it is off, to prevent accidental movement of the ring switch.
This works better than the hand hold version by far, but this modification is not for the faint of heart and a lathe is a necessity. Yesterday I took it down to 40 m and compared it with the new light I just built, SST90 and custom driver and the new light blew it out of the water. So all things considered, I'd say the D-35 is a decent light, but for that price one should be able to do better. I'm taking it cave diving at the end of this month, so we'll see how it works in the caves. On thing though, if you buy it and throw it in your gear bag with batteries installed, be careful the ring switch can easily be turned on by accident and roast everything around it. I leave it disconnected from the battery pack until I am ready to dive. Underwater the switch is great, but the manufacturer should have created some kind of locking mechanism when it is off, to prevent accidental movement of the ring switch.