No stress over annuals.
No fear over the unexpected $35,000 overhaul bill (if you have an experimental engine).
No getting in line at your local A&P and waiting an unknown amount of time for them to complete small repairs.
Ability to improve the safety of your airplane at your will.
Feeling in control of your own aircraft instead of constantly being at the mercy of the FAA, the parts industry, and your local repair station.
It can be hard for those who have only lived in the certificated world to really appreciate the experimental world. I know I didn't.
I will say, however, that taking on the responsibility of maintaining your own aircraft was a lot more than I expected. I used to blindly fly my Cardinal, well forever, without pulling the cowl. And only taking to the shop for annuals, oil changes, and repairs. I placed a whole lot of blind faith in Mr. Cessna and my A&P.
Looking back, I feel that blind trust was woefully misplaced. I was truly ignorant because I simply did not understand, or consider, all of the potentially serious failure points of my aircraft. After building and flying my own EAB I am now aware of all of the many, many, points of failure that exist in every aircraft that I never before considered.
"There's hundreds, even thousands, flying that only have their cowls pulled at annual or oil changes. Why should I worry about what's going on underneath the cowl in the meantime?" I think this is the mindset of many pilots.
It is not my mindset anymore. When you start living with an aircraft that is completely under your control you realize you have a whole new responsibility towards safety for you and your loved ones. It's on YOUR shoulders and no one else's.
I pull the cowl on my aircraft about every 10 hours to inspect. I know every wire, every connector, every support, and every component. And I know how easy it is to have a failure of them at any time. So I study maintenance issues, tweak, inspect, update, replace, clean, double check and improve, constantly. I estimate I spend 2 hours of inspection and maintenance for every hour I fly. Probably more.
I absolutely hate maintaining my own aircraft. To me, there is nothing enjoyable about it. It's a painful, time-consuming chore. But my wife flies with me and I will do every single thing possible to ensure it is as safe as possible. When I roll down the runway I KNOW that everything under the cowl is as good as it can possibly be. Yes, things can still go wrong, but I know I've done everything to put my aircraft in its best possible condition. I have not relied on someone else to ensure my safety.
Yet the burden, time, and effort of maintain my aircraft is still better than living under the thumb of the FAA (To be clear I'm not an FAA hater, its just the system and most of it makes sense to me). I have lived with the helpless, frustrating feeling that the FAA rules, at times, are just wasting my time and money for no real benefit. To have all the control in their hands and I'm just along for the ride.
I like being in control of my own schedule, my own time, and my own money. The burden of maintaining my own plane is far better than constantly being at the mercy, and control, of the FAA system. Also, regardless of what others may say, it's a heck of a lot cheaper....