A cat in beam seas can be a little annoying - and as my first captain told me, "The ladies don't like it!" Slide left or right 10 or 15 degrees, much better ride. Seas directly off the stern are not my favorite, not only is it a lousy point of sail, but mostly because Otto doesn't deal well with it, and then the [censored] end swings all over the place left and right. Again, bear off a little, and the ride is much nicer! But even with those points of sail, you'll probably find it smoother - if different - than the ride in a mono.
Play with it - you'll like it.
As for locking the wheel when maneuvering with just engines, yeah, you can't really get the knob tight enough - at some point the wheel tries to spin. Once I tighten it up, I keep my knee locked into it, and it doesn't spin - I am generally not moving that fast (intentionally). And it presents another opportunity to use another one of those eager but idle crew - "Here, hold the wheel right here, no matter what!" lmao
Keep Smiling!!!