What is the difference between a certified and uncertified EFIS in your opinion and how would that make any difference? The Dynon Skyview is AFAIK still uncertified, has synthetic vision, terrain alerts, traffic awareness, autopilot availability, approaches and other features. Is this less safe than a certified Avidyne in a Cirrus SR20?
I hope that is a rhetorical question. Certified means it has passed the tests required to be able to say it is safe, non-certified is unknown. If its passed the tests required for the specific operation then it will be reliable for all the situations posed for it in the conditions it could face in that type of flying, and or limitations specified where it will not be 100% reliable. Certification may or may not include installation requirements, that make it more than a dash ornament and integrate with the aircraft systems and pilot ergonomics. Things that come to mind for this type of topic is topple limits for attitude instruments, non certified it could topple in moderate maneuvers making it useless in recovery from unusual attitudes. Therefore its not going to help you recover an aircraft in a UA when thrown in cloud suddenly.
Also to add Binghis' point as to how weather, altitude, heat and so on proof the unit is. Some of the recent uncertified eperimental stuff is fantastic, but saying all new EFIS systems will perform the same is misleading. Some units will have been produced with far superior performance to certified stuff, but not certified to keep cost down, however that means you never quite know why they didn't bother to certify it.