When I switched from a WB to a ZTR, the increase in productivity was astounding. I was able to finish 8 or 9 lawns in the time it used to take to cut 6.
I find that the stander is almost as productive as the ZTR. It is way faster than a WB. Faster loading/unloading, faster in tight areas, faster backing up, faster turning...it all adds up.
Around here, you really need a bagging machine for some lawns and for cleanups. So most solos starting out go with a WB, then switch to a ZTR w/vac when business picks up. That is what I did. When I needed a 2nd mower to keep up with the lawns, the stander seemed like the best choice. And it was.