I've had both...Suarez for a 19 and currently an ATOM for a g17.
Both are very good. I no longer have the Suarez or the g19, but only because I like the G17 platform better and bought a second one (Glock 17, not ATOM slide).
Some people don't like Suarez International, however I can say they have excellent CS. I had an issue with one of their milling jobs on a 19 and they went ABOVE and BEYOND to correct the problem and really surprised me. As far as their own slides? It was very well made.
I only went with the Unity Tactical ATOM because I am purchasing another Aimpoint micro and want to put that on my G17.
If you just plan on running a particular optic, the Suarez will suit you just fine, and I personally would buy another without hesitation.
Only my personal experience.
Also, Suarez sights and magwells I believe are made by whoever also makes Salient Arms' sights and magwells. They are the exact same, just different logos.