They're pretty good...in the right scope. IMO the focal range isn't good for a C11...for a C8 it would be a better fit.
I'm not being funny, but if changing eyepieces is a "real pain", then maybe this isn't the hobby for you
Seeing - especially with a scope with the focal length of a C11 - comes and goes regardless. Pick a focal length, stick it in the scope and be patient. As the seeing will come and go - and there is nothing we can do about that - just sit and watch and every now and again you will be rewarded with moments of decent seeing that will make it worthwhile.
One eyepiece that I find works well in my C11 is the Pentax XF 12.5mm. The magnification isn't too high, so you increase your chances of getting more moments of good seeing, it's nice and sharp and the eye relief is good for specs (20mm iirc).