Dry-firing last night, and I noticed the std trigger on my RRA lower was kinda heavy.

Is the NM trigger a must-have?

If you're using it for target shooting, yes it's a must have.  If you're using it in the field then you'll want reliability over crispness and will be better served by the stock trigger.

I have 2 one on a RRA M-forgery 1 on a Colt H-bar. I would highly recommend them! "like breaking a fine glass rod"

If you don't want to spend the money on a NM trigger, which will be $100 and up, try the Wolf Trigger Spring kit.  Costs about $10 and made a world of difference on my stock trigger.  Much lighter, though it didn't help the creep or smoothness any.  That rig just barely made the 4.5 lb test last year.  Year before they had to bounce the weight up and down to get it to trip.  Yes, everyone in line thought that was very funny.

I've since gone to RRA two stage and love it.  Added fifty points to my scores. I'm now merely bad, as opposed to horrid.  

I got the Armalite NM trigger in my first AR, with the Eagle lower.  I've got thousands of rounds through it, and it still feels great.  I've never experienced the problems some folks who have the RRA have.  

I've done the 15 minute trigger job on a couple of my rifles, and put the reduced springs in one of 'em.  It works great for general all plinking type stuff, but it will never be confused with the match trigger.  Of course, it's a LOT cheaper.  I had one rifle that was downright painful to shoot...I could feel the tendons in my wrist stretching after about 20 rounds....the trigger job made a world of difference to that rifle.  

I love my Armalite NM, it is getting better with each pull of the trigger. I swapped out the Armalite single stage in put it in my Bushmaster M4. The Armalite triggers are pretty good.

I have a Jewell on my varmit rig. Wish I had enough cash for all my AR's to have them.

I have the RRA trigger and it was worth the money.