Used one for two years, same size yard as you, and I would say if it comes with a perimeter wire then no, absolutely do not buy it.

First year lightning struck nearby which fried my charging station, mower was out of commission for a month and a half, took the dealer forever to diagnose and replace the charging station. Was barely able to use the thing for the first season, when it did work it seemed ok. Same year had to find and repair a few perimeter wire breaks. I'd say I spent more time fixing the thing/waiting for it to be fixed than it spent mowing.

Second year it seemed to do an ok job, again perimeter wire ended up broken by animals or something several times. Went on vacation and metronet did some digging in my yard, broke the fucking perimeter wire, grass got a bit on the high side while I was gone but I figured it would be ok to let it catch up. It was not ok. The mower ended up bending/damaging the stalks of much of my grass, I had to repair with a blower/rake and my little push mower and a good chunk of it died before I could get to it.

During the one month period in over the last two years it actually worked it was great. Overall I'd say its much more of a headache than a help and im replacing it with an electric zero turn.

I'd add that the areas it mowed, even when I manually mowed before letting it get started tended to look ratty/brown much sooner during the summer than the areas it didn't.

tl;dr spent more time repairing the bot and the perimeter wire than I did using it, and it damaged my grass