The MLZ2 is GARBAGE. I have two of them in my bedroom and I can spit to the gateway and they still have issues on occasion.

 The WiFi remotes will roam on a real wireless mesh system and be as reliable as they are in a one room solution. We have had great success with the Motorola Symbol products. You can also use the REAL Cisco mesh system however neither of these solutions are inexpensive. I have to agree with Alan that you are asking for problems.