I got my slide back from Jagerwerks today. I haven't had a chance to shoot it yet, but I'm pretty impressed with the overall package.
In comparison to my ATEI cut slide for an RMR the overall optic height is VERY close to the same, but the 509t is just a touch taller. I don't have a way to accurately measure, but I'd estimate its 1 or 2 millimeters. (The attached picture from the front more accurately shows the difference than the picture from the rear.) I do not feel the additional height will impact concealment in any way, but the height extending over a longer length than the RMR could be a concealment factor since there is height further away from the belt line.
The usable window for the 509t feels huge in comparison the RMR. You get more useable space on the top, but also more usable space at the bottom since the bottom of the window and sights sit lower.
The "tube effect" does seem to help a bit for initial alignment after doing a few one handed presentations. If I'm slightly off in my presentation my brain seems to be able to instinctively fix it more than with the RMR.
The glass has significantly less blue hue compared to the RMR, and the distortion is very similar with the 509t having just slightly more at the edges.
This is all just first impression, but if everything holds up during live fire this will be my new carry option and I'll send a Glock 19 slide to be set up to match.