I ended up with the 915B, almost 3 years now.
I have a question on putting grease in the 3 spindles. Is there a weep hole? I have not found one and without it how do you know when it has enough?
Once I just kept pumping until it came out of the bottom past a seal I presume. (it took about an entire tube of grease) Needles to say that made a mess in the deck once I brought it up to speed while cutting lol
I've been very happy with the unit.
The negatives are tire depressions in the yard. Some places you can't rotate the pattern you cut and it leaves a slight depression. I may use my walk behind in these areas. (around planter beds and the house, fence lines etc.)