I have exactly that...the D-10A and EMS D-10.
I've been fairly happy with the setup. I've found that I have absolutely no problem whatsoever seeing the stuff on either unit.
It always cracks me up when people argue that it's too small. The text is as large or larger than the text on a traditional steam gauge and the AH is certainly bigger than a mechanical AH. As far as the EMS goes, well, the size of the text on the EMS D-10 is way larger than the text on traditional steam gauges. Of course this is a subjective thing and I can completely understand the bigger screens, especially for people who are farsighted.
Of course, I'm only 32 so farsightedness hasn't kicked in yet so maybe age has something to do with it.
For what it's worth, here's my panel:
If I were to do it again I would probably flush mount both units. My logic for not flush mounting them was that it would provide me future flexibility in changing my panel around. That logic has proved to be worthless because quite honestly it's very easy to hand cut a new panel. In fact in was one of the more enjoyable parts of the project for me. Also mounting them this way I kept the center rib for my tip-up canopy that annoys so many folks. The only modification was to countersink for the #8 screw that's sitting right behind the Dynons (you can sort of see it in the picture).
Also, I'll tell you that having a full blown engine monitor is so nice. This weekend I was flying back home with my wife. I noticed fuel flow was higher than usual. I also noticed that my #3 cylinder was peaking way before the #2 which usually peaked about 5 degrees sooner than #3. Quick in flight mag check...yep...I had a solid miss on the left mag.
After landing, I switched again and clearly observed EGTs on cylinder #3 drop off quickly when I switched to the left mag. So basically I completely diagnosed the problem without ever getting out of the airplane. I knew that the #3 plug on the left mag was not firing. Later in the day I pulled the plug and sure enough it was fouled and could stand to be gapped so I cleaned it with my EAA chapter's plug cleaner and gapped it. Put it back in and voila...everything was good again.
Then I pulled all the plugs and did all of 'em.
I usually try to run lean on the ground but sometimes I forget when I land and taxi back to the hangar. I guess I need to add that to my checklist.
Sorry for the aside.