Output watts is not as important as the quality of the antenna, transmitter and receiver. As Rick pointed out, the DLR transmits on the 900 MHz band, meaning - in theory at least - they will be inherently better in and around buildings than an identical-quality radio in the 400 MHz band. It’s just physics; the shorter-length radio wave can penetrate better through doorways, windows and between rebars.
This of course is pretty minor, as technically there is not a huge difference between 400 MHz and 900 MHz. But in real world conditions, I have tested the DLR and DTR radios against the best in business-class and FRS radios, and in an urban environment, with lots of buildings and trees, the DTR and DLR easily bests every single handheld radio I have ever tested.
In fact, as I once reported in these forums as a review, the DTR radios were so good that magnet-mount external antennas on the roof of a vehicle actually degraded the performance, compared to just throwing it inside on the seat. The DLR uses fixed antennas as opposed to the replaceable ones on the DTR, but in my real world tests, the DLR was only about half a city block shorter in range before they cut out completely.
One major difference is that digital radios send out a short “handshake” signal to make sure another radio is in range. This takes about half a second or so, and one doesn’t even do “radio checks” anymore, as a quick push of the PTT will tell you when a radio is within range. Being digital, they either receive with 100% clarity, or they don’t receive at all. There is no fuzzy, scratchy transmissions at the edge of their range like analog radios.
If you are working with the great folks at buytwowayradios, then see if they will send you two DLRs initially, and find out for yourself if there are any dead spots. They are an expensive investment.
Plus, if you don’t like them, they have high value on the used market too.
They also have an advantage, being digital, that one radio can call up another radio individually and have a conversation, while others can still talk on the same “channel.” Analog radios cannot do that.