In simple terms (not being a technical person myself) comparing to analogue, it has better audio quality, better signal quality, uses less battery, supports text messaging and operates at half the bandwidth thus is like 2 repeaters in one (see time slots menu).
As per the graphic, digital signals despite not always getting the same distance as analogue signals, the signal stays above the minimum acceptable audio quality line for longer. Digital signals also do not have as rapid a decline as analogue.
DMR radios are mono band. In the UK, the majority of DMR repeaters are on UHF (please check the repeater listing). As DMR is a commercial system, there are some really well established brands in the market.