The MI handguards and the troys are both nice IMO. I have the troy right now on my 11.5 bcm but I am planning to swap over to the BCM key mod one of these days because it is a lot lighter than the troy rail. I know its not “round” but its pretty close. So if weight is a concern that’s what I would choose.
The Samson is round and feels alright. Noveske keymod and bcm KMR are very good ergonomically. Finish on BCM KMR is sub par in my opinion. Geissele mk1 is my favorite. Oval shaped. Lots of options these days.
I put a CMR on a DDV7 and really like the weight and feel shooting this rifle. Fairly easy installation. It’s been through a couple of classes and a lot of rounds.
Lots of good options mentioned.
I was in the same situation as you. I wanted something super slim and durable. I did a bunch of research and eventually ended up with the Novekse NSR rail. heres a photo of me wrapping my hand around the rail. I have pretty small hands and I can get a VERY good C-clamp on the rail. Hope this helps you a little bit. good luck!
I really like the MFR on my Daniel Defense V7, but if I were choosing something today, I think I would give the ALG rail a shot http://algdefense.com/rails.html
NSR was worked OK for me. I suspect there are at least a few other brands that I’d have been just as happy with. For gear-obsessors, it’s easy to overthink this purchase.
It is very hard to find data on the outside diameter of the Troy Alpha or the Noveske NSR.
The newer Apex is 1.970", The Rainer from above post is 1.80" and the MI Gen 2 is 1.50".
I felt the ALG Defense at SHOT and truly liked that option and support the Giessele clan to the tune of three triggers already.
For weight considerations and specification so far the MI remains in the lead. I hope someone would post the outside diameter of the troy and NSR options.