I don't know about being worried by "smallish boxes storing huge amounts of energy" (presumably you're thinking of Lithium ion batteries?). Just try calculating the energy in two 20L jerrycans of petrol!
I used to fly a petrol powered DG808, 20L of petrol 4 inches from your right shoulder; now I fly an electric Antares with cables carrying 280V DC immediately behind your neck (but with the batteries in the wings). I feel safer in the Antares. In both these gliders the pilot wears a parachute.
The MCR01 I used to fly had 80L+ petrol immediately above your knees and no parachute system.
None of them feel safe to me.
So to return to the original question: no I haven't flown an electric airplane and yes I've flown several hundred hours in an electric powered sailplane but with a typical powered launch time of 6 minutes and an absolute engine run time of about 11 minutes my experience and range is very limited!
On the plus side the batteries are now over 10 years old and only 4 of the 72 cells are down to 97% of their original capacity. Their predicted life is about 20 years, probably just as well as their replacement cost is the same as buying a new Lycoming...