Makita product lines comparison
The Makita XMT series of tools is marketed toward tradespeople and professionals while the DMT is for the mass market.  Little outward differences but generally there are significant differences in durability and reliability.  You'll find DMT at big box stores and the like.  Usually you'll only find XMT at professional supply outlets.

If you are just going to be using it for typical homeowner duties, the DMT is your best value.  If you expect to use the tool to make a living, then consider XMT.