I've had two Remco units and the actually disconnect hub works really well. Occasionally on vehicles that are not popular, like my 2010 Nissan Frontier, there brackets that attached to the rear end to do the shifting were terrible. Luckily, they sent me two different mounts, because they were not sure which one would work, and I was able to modify it into something that was reliable.
I bought the new driveshaft so that I could replace the OEM one if necessary. The new one comes unbalanced because you have to install your own u-joints and yoke. You need to get it balanced which is relatively inexpensive. The splined unit that actually shifts the driveshaft in and out of gear can be locked into position in two spots, 180 degrees opposite of each other. When you get your driveshaft balanced, make sure they balance it in both positions. You'll understand what I mean when you look at the unit. If you don't, you can get a shake in one position and be perfect in the other.
Don & Mary
2014 Newmar Dutch Star - All Electric - 450 ISL
2016 GMC Canyon 4WD Crew Cab