1/3 acre here as well. All cut with a 21" self propelled Snapper commercial model bearing a 5 horse OHV Honda engine. I've only had it a year, after wearing out another snapper with a 6 horse Briggs in 4 years. IMHO, the Honda has more power than the Briggs ever did, despite the "drop" in power ratings. So far, so good...but it does take time. But what the hell...I'm retired, have the time. And just going for a walk for exercise bores me. I'd rather be doing something productive AS I'm walking for exercise...
BTW, the Willamette Valley of Oregon produces 90% of the world's grass seed. Trust me on this...grass grows well and fast here...during the busy season, I often mow 2 times a week.