a small nit -
There is nothing about the first gen Dynon units which precludes safe and effective IFR flight - been there done that for years.
Who said they weren't? I didn't even mention IFR.
EFIS selection is slowly turning into a religious debate like the primer wars. There is no one size fits all answer, but people seem to feel a need to defend their decisions regardless of knowing the requirements of others.
The units I mentioned are all great as a six pack replacements, which are perfectly acceptable for basic VFR operations. As you start to add other requirements, some may remain as satifactory choices, others may not.
IFR means too many different things to too many different people.
I take a more systems approach to IFR. There is the equipment you need to be legal with the FAA. That's the simple part to evaluate. Then there are the system attributes that allow me to sleep well at night. Again, this is highly subjective. We all have different risk factors that are acceptable to us.
For example, would you want your autopilot to run the same code base from the same vendor as the EFIS? What if there is a software bug or a system hang in the EFIS? What would action would your AP take? Or would you like your AP to run a different code base from a different vendor? This would allow the AP to run indepently of the EFIS, should an EFIS fail for whatever reason. Can the AP keep the aircraft wings level, flying upright, and on the same course in either of these scenarios?
Is an AP required for IFR, of course not, but it sure makes things significantly easier and reduces work load. The different EFIS vendors have different strategies on how their systems work. All I'm recommending is that you understand this before you select a vendor and/or a particular product. There is more than just checking off whether or not it meets the minimum requires for IFR, or VFR for that matter.
bob