I just got one two weeks ago. It's such a new product there is very little discussion to be found, and zero long-term ownership experience. So here's mine so far:
[tl;dr] Despite some teething issues with the new product from Ego, I think this is a good mower if you enjoy electric OPE and need to mow up to an acre or so of surburban-style grass. Definitely geared toward residential owners, not business users. If you're into high-speed mowing or have a giant plot to mow, it might not be for you. As long as it remains reliable, it's a keeper.
My experience so far: The first mower (yep, I'm on my second unit already) did a great job on my front yard, but suddenly died when I hopped off to open the gate to cut out back. Batteries were good, charge >90% power, but the mower just refused to turn on, like a fuse or relay went. Troubleshot with Ego on the phone (their CS was helpful and professional- a nice surprise!). This mower has its own customer service team, and they have a direct line to the product development engineers. Bottom line: My options were get it to a service location 2 hours away, or have it swapped out with another unit by the dealer (big box hardware store with a big blue sign... you know the one.)
I elected to swap it out, since I'd had it in my possession less than 24 hours. Lowes took care of me with minimal fuss, even dropped off and picked up the old mower, and now I have a working copy. Same batteries and charger as the original.
After that hiccup, all seems to be good! I've mowed twice with it so far, and it's easy to use, quiet and clean, fun to drive, and charges quickly. I find the seat very comfortable, and the controls are intuitive. Drives like my parents' old Dixon ZTR. The Z6 seems to have plenty of power- I mow my thick, tall fescue on a medium blade speed (2 bars out of 4), and get a nice cut. I haven't run into a power limit yet, and there are some impressive torture tests you can view on Youtube. However, a Bad Boy, this ain't. You won't be mowing at 15 mph and leaving stripes with a Z6. Top speed is about 8mph, and I estimate I mow around 4-6 mph. Makes mowing a good Sunday afternoon "chill" chore. Or after work at sunset, because it has lights all over it- a nice feature I didn't even know I wanted.
All in all, it takes me about 25 minutes to mow my 1/2 acre suburban lot with trees, bed, and fencing, and my yard uses about 40% battery. I don't think you'd get the advertised 2 acres with this in anything less than ideal conditions, but it should handle a 1-1.5 acre lot with beds and trees on a single charge. Could mow more if you add additional batteries. Charge time is about 2 hours, although I've only needed to charge it once so far.
There are a couple of warts- the Bluetooth interface isn't mentioned at all in the manual and can be a little fiddly. It doesn't "pair" like other BT devices, you have to hold down the "settings" button on the mower, open the Ego app, and then tell it to connect. Then and only then will BT connect. But I did follow customer service's instructions for updating my mower's firmware (again, not in the manual- why?), which is said to solve some "known problems"... I had no problems updating the firmware once I got BT connected.
This mower also has a LOT of plastic on it- generally more than I'd like. The Ego logos are just stickers on the outside- they didn't emboss or color the plastic. Kind of cheap feeling for a $5000 mower. I might eventually remove them and have a "debadged" mower. If it gets wet, they'll peel.
The stamped metal deck seems OK, although it rattles a bit during high speed driving. I adjusted and leveled it immediately, which minimizes the rattle. It's easier to adjust and remove than most gas riders I've seen (Dixon, Grasshopper).
Haven't tried the deck-wash system yet, but I clean it off using my leaf blower (also Ego) and it stays fairly clean.
Hope this helps.