I can't offer any feedback on the Tru Glo, but I can for the TriViz...
I installed the TriViz last year on my M2. I was skeptical, at first, since it is made of "plastic". That has not been an issue. I don't use my gun to pound nails or paddle canoes, and I truly believe any drop or fall that would damage this sight would also damage a scope or red dot.
I like it because it is adjustable, to a degree (plenty enough for my needs). Left / right is adjusted with a screw on top of the rear sight - gang adjust. Up / down is adjusted with changing out the post height on the front. My M2 wanted the lowest front - they give you 3 options.
Another advantage for me, since I use this gun for waterfowl, dove, etc. is the fact that I could remove the rear sight. I ordered a couple of spare light pipes from HiViz, and I just put a regular round red post in for wingshooting. The extra light pipes are cheap, and changing them out is pretty simple.
http://www.hivizsights.com/product/replacement-litepipe-for-bird-buster-tri-viz-tom-buster/As far as cons, I'd say you just have to be careful with the screws / nuts on rear sight. TINY. Take your time, and it's all good.
Visibility was / is excellent...