Yes I know, I'm a little behind the times with this one...

I'm considering getting one of these to mount a RDS on my 47 variant, probably a Trijicon RMR. However as I look at the design I have to wonder how it might effect accuracy and harmonics since it essentially hangs off the barrel? For those that have one, what is your experience with it in regards to effect on accuracy? Thanks.

I'm not sure how the MI attaches to the barrel, but the Ultimak, which also clamps to the barrel has a reputation for slightly improving accuracy because it acts like a barrel strut and increases barrel stiffness.

I found the MI handguard opened up my groups, I personally did not like it. Some people say they don't and others would agree with me.
The fact is that the clamping surface is quite large and I definitely noticed my groups opened up some, it was noticeable even at only 50m.

The Ultimak gas tube clamping system is different, if installed as directed it does not touch the gas block or rear sight block, adding a small measure of free floating if you will.