Are these comparable in quality?  The BM is less expensive to start with and I can get another 10% discount through BM.

I don't want to but "junk" just to save a few dollars, but with a new family addition, I'm on a budget.

Thanks

My little brother just bought the BM and I just got a #40A. I like the #40 better and he agrees. The biggest negative IMO is that the BM sight has to use two slots on your flat top so it has to be mounted one slot forward of where the #40 can be placed. I want my BUIS as far to the rear as possible.  

The BM push button is slicker than ARMS' latch but how often are you gonna be deploying the thing anyway?

The ARMS seems just a little more bullet proof.

The ARMS 40 is a substantially better design.

Try using the push button in the cold weather with heavy gloves on, in a hurry:)