You described the conditions in which you were mowing so, I don't think your review is invalid at all. Like me, you seem to feel that the mower is not perfect, but still an adequate replacement for a smaller gas mower used under 'generally' typical conditions.
I've read that the battery charge indicator lights are at 75%, 40% (I think?) and the last one at 10%. I try to wait till I've discharged the battery or it's down to just 1 light before recharging as I've read it is charging cycles that contribute most to the demise of batteries.
Consider taking a file to the blades and sharpening them. I also dump the clippings out of that mulching plug occasionally. I have previously threatened to fill it's 'chambers' with expanding foam but haven't done it yet.