As someone that has shot trijicon, meprolight, and even ameriglo 3 dot sights, I have to say that I now prefer the 2 dot system like the I-dot. I was intending on changing the height straight 8 on the Dan Wesson valkyrie I had, but I gave them a try. I found that I was more consistent and faster than with the 3 dot setup. This is in part to being left eye dominant and right handed.
Look at it this way. with the three dot system you can better align vertically, but can shift left and right between the two rear dots. With the 2 dot system, you are better at aligning horizontally, and more likely to shift a little up and down. This helps me personally, as someone that is cross dominant.
I have also let friends shoot my 2 dot setup and they have been really liking it as well.
Currently I have three slides with Ameriglo I-dot. Having both the U notch rear and the square rear, I prefer the square rear. I also have an M&p pro with heinie straight 8's. The only gun that I carry that doesn't have these sights on it is my RMR mounted slide, which extra dots can distract from the red dot, so they are just straight blacked out irons front and back.
I think you will find them growing on you as you spend time with them. I will only use these types of sights going forward other than an optic mounted slide.
Plus, ameriglo has great customer service from what I have experienced.
Starting from the left: M&P 2.0 compact 9mm with U-notch i-dot, M&P 2.0 5" spec series 9mm with square notch I-dot, M&P 1.0 40 with Heinie Straight 8's, Glock 29 with square notch I-dot. The slide with RMR is fore my compact frame.
2.0 9 compact sight size and options
Linear Mode
