I use a ARMS #71 folding front sight in tandem with a Troy di optic rear. I bought the ARMS just to throw on until the Troy front sight came back in stock at my local dealer. I ended up canceling the back order for the Troy front sight because the ARMS front works great with the Troy Di optic diamond rear.
The "wings" on the front sight line up perfectly with the Troy diamond rear apature. It seems plenty strong enough and its actually spring loaded. All you do is hit the flipper and bang... the sight is there. The only thing I dont like about it is that it doesnt lock in the open position. It just springs into the up/active postion and is kept there by a pretty strong stainless steel spring.
I run a 3.5x35 ACOG so I just use the sights as back up, I also have a TNVC red dot mounted at a 45 defree angle as a third form of backup. I love the light weight design of the ARMS and I prefer the type of polymer they use over the magpul plastic sights. The ARMS sight seems to use a tougher glass filled polymer than the magpul's but thats just my opinion.
. I think I would go with Troy sight front and rear if they were my main/only sighting device. The ARMS 71 is smaller and shorter than the Magpul buis and IMHO the ARMS are superiour to the Magpul poly sights.
Go with the ARMS if you want polymer sights for back up, go with the Troy if you want the strongest/best sights around or if you only run sights....