I've been intrigued by the cordless options now available too. I have a bit over 1/3 acre and it takes me about an hour to mow with my Honda 21 inch gas mower. I think the Ego would work for me too... and add a blower and string trimmer .... all using common batteries. I like it.

The negative, from my brief research is that while I would no longer have to buy non ethanol gas and change oil for the mower and mix oil and gas for my 2-smoke trimmer/blower, I'm not convinced that the expensive Li-Ion batteries will last much beyond 5 years. My gas equipment far exceeds that sort of lifetime and the cost of the batteries is significant. So while converting to cordless would likely work for me, I think both the initial and long term cost would be significantly more than continuing to use gas equipment.

I would love to be proven wrong about my conclusion.

The Ego I would go for would be the self-propelled 21 inch version.. not because I need self-propelled, but because I want the 7.5 Ah battery that comes with it. And replacing that size battery (likely needed to run my equipment for an hour (mower) trimmer (30 minutes) and blower (20 minutes)) would become pretty expensive as I anticipate needing at least 2 batteries to start with.

The mower lists for $599. The spare 7.5 Ah battery shows as $379 at Home Depot. There's $1000 just to start.. and no blower or string trimmer yet.

So the economics do not seem to justify the move... even if I sell my current mower in excellent condition for $400 or so. I can still buy a lot of gas and oil for $600. OTOH, my ancient 15+ year old Ryobi string trimmer/blower is on its last legs, so I need to consider my options.