The Dmc should have good coverage if you have enough base stations or repeaters and is friendlier operation than the Engenious, as it acts just like a norstar set.
The engenious is like a cordless phone on steroids.
They have great range but not as easy to use the features, altho you can program most of the ones you need.
I find for most purposes the T7406E is the easiest to install and has pretty good range if the base unit is installed in a good central location.
I have a couple 7406Es working in a big box stores and they have no dead areas inside and some service outside if you are not too far from the building which is all metal.
I have a DMC working at another ,but it requires a few base stations and repeaters inside and a couple repeaters outside it covers the whole lumber yard .The big problem is they don't have a weatherproof repeater for outdoor use. I built a couple of small boxes using fiberglass and epoxy to put them in and have had no trouble for about 3 years.I tried using a plastic electrical 6x6 box but it just killed the RF.
also they are not cheap$$$