I bought this item as a refurb from Amazon. I have it for a week and a half and I really needed this as it's been two weeks since my grass was cut and I have a very tough HOA in SC. For one thing, I am extremely satisfied by the refurb as there is NO physical damage to the product. It was well packaged, I didn't care that it wasn't in original manufacturer box as the box was thrown out anyway. The order came with a battery so make sure you read carefully before you purchase the item unless you already have batteries. I have .36 acres, front is slightly sloped and side of the property is flat, the backyard is on a 40/45 degree slope. Battery lasted 35 minutes to take care of front and side with 1 battery light remaining. I didn't do the back yard, see my separate review as I purchased a secondary battery. My list of pros and cons about this item, no specific order.

Pros
1. Price was perfect for a refurb with a battery
2. Light enough to push up and down a hill as this unit is not self propelled
3. No need to worry about gas and oil mixtures (Had gas lawn mower in the past)
4. Storage is great as it stands on the inside wall of my garage
5. Mulcher option is better than my previous gas mower
6. Much quieter than a gas engine mower, I mowed my lawn after 6pm and my family could not hear it inside the house

Cons
1. Better get a second battery, not much but just wanted to specify as I have .36 acres
2. Battery takes 2 hours to charge (40v 4Ah 123Kw), again, not a deal breaker for me as I purchased a second battery
3. Removal of the battery is a major hassle, others have also mentioned this.

Do yourself a favor and buy this bad boy. It's lightweight, efficient, and fits in the trunk of a Honda Civic. That is all.

This is a well made, powerful mower.
I use it for trimming and doing a fenced courtyard that I cannot get my rider into.
Does a great job. Holds two batteries, but one is not connected, just stored. When battery dies, you must swap (Kobalt electronically switches). Batteries are a little tough to get out (of all tools!) I have added a little pull loop to battery to aid in removal.
Stores vertically with small footprint.
Thanks for reading.

I really wanted this to work as advertised and be better than a gas mower. I set out on a lovely Saturday morning to cut the grass. It all went fine until it didn't.

The batteries provided are pretty worthless in terms of capacity; I'm attaching two pictures to show how much grass got cut on one and then the second battery (both fully charged -- the length of the front yard is about 80'). At the current rate, I expect to be done with my yard sometime Sunday.

The deck is also not parallel to the ground based on the rear wheel height (there is one lever for all wheels) so the front will always cut a little lower than the rear, which wouldn't be such a problem except the max height on the wheels is a good 1-2" lower than my gas mower. I suspect this may have contributed to the horrible performance time but not significantly.

Will be contacting Amazon for a return; with the exception of the terrible battery life I enjoyed the mower for the 30 minutes I was able to.

--UPDATE--
Gave it another try and since I was paying attention this time, can provide more detail.

Batteries:
The batteries lasted 10 minutes and 6 minutes, respectively, from full-charge. I suspect that the real problem is that they over-heat so quickly as the 6-minute battery still had 2 bars left when the mower stopped. Design flaw (it was 79 degrees today while 84 degrees last week). With the slightly cooler temperature I was able to double the amount of lawn cut (whole front yard!)

Mower power:
There is a "mulching option" (plug all the openings) but this mower is under-powered to actually mulch the cut grass; it largely just sits on top of the lawn and turns brown which makes the yard look like crap.

Over-all:
If you have a small yard and like to bag your grass and have some extra money to throw at the problem, this is for you. While I certainly appreciate the aspect of carbon-neutral living (have a nice solar array) this mower is too underwhelming to replace my nice gas mower. Back to Amazon you go....

Very happy with this purchase. Pretty easy to push. Assembly was simple. I wish the battery lasted longer, but that's not really a fault of the product I suppose. They do have a storage compartment for a second battery which is very convenient. The mower does a good job keeping the grass in the bag, which removes easily for dumping. There isn't really a good way to know it's full other than it feeling heavy or if you start to see grass clippings being left behind. Adjusting the cutting height is very easy and you get five options. I've got no complaints.