The self propelled mower is rear wheel drive yes? How to back up in corners? I'd decided to buy one this weekend but I've always owned front wheel drive where it's easy to raise the front wheels to back up.
If you let go of the drive lever just before you get to where you need to back up and let the mower "coast" for a few inches, the propel mechanism disengages and you can then pull it backwards. Many people report a short learning curve to get fluent at it, and once figured out it's no problem.
To be explicit the mower does have an anti-rollback feature to protect you on a slope. This can make backing up difficult if you aren't aware of it. You have to disengage this by rolling slightly forward after letting off the self-propulsion lever. If you don't disengage it the mower won't roll backwards making getting out of a corner awkward. I personally am a big fan of the feature since I have a lot of slopes to mow and I can pause without getting run over by my mower.