Xref: 127.0.0.1 alt.home.lawn.garden:4419

I have a 31cc Ryobi 775r (gas)its 4 years old and has been flawless.
My yard is 150x65' so not much bigger than yours. I never have used an
electric one. I do use an electric leaf blower where I work and can say
I dont like having to drag the cord around, snagging, accidentally
unplugging trying to unsnag the cord. I have used a gas blower at a
prior job liked it much better. For this reason is why I bought a gas
trimmer. Power wise mine is more than sufficient, maybe too much power.
I have taken off a few chunks of siding a small electric one may not
cause this(not sure though). Too on mine the shaft can be rotated for
edging the sidewalk & curb.
There are cordless electric trimmers that may suit you.
I would say for your size lot gas vs electric comes down to how
comfortable you feel using a gas one, having a separate gas can for the
oil/gas mixture {OH I get about 4 trimmings per tank} plus you can at
times have the smell of the exhaust linger on your body (something my
wife cant stand).
If I was in the market for a new trimmer I would definitely check out a
cordless one but corded electric would be last on the list.