OK, made a trip to Homedepot and the Ryobi was lowered to $359. I grabbed it because there were only 3 left, and I know that an unopened return would be no problem if I ended up ordering the B&D. Here is my dilemma:
* B&D has many satisfied users throughout their cordless line
* B&D front and rear wheels are the same width
* B&D is newer
* B&D is lighter by 2 lbs (38 vs 40)
* Ryobi has lower cutting height .75" vs 1"
* Ryobi has 3 yr warranty vs B&D 2 yr
* Ryobi is easier to return
* Ryobi batteries are marginally larger than B&D
* Ryobi is more proven since it has been out almost 2 years
Not sure which mower is narrower (for storage) or which company has better customer support. The Ryobi seems to have a considerable edge on the list, but there is something about the B&D CM1640 that interest me. It is literally 7 clicks away on Amazon. Decisions, decisions...