The answer might be location, location, location....
With east coast light pollution and the generally poor seeing from suburbia, the best I am getting is about 0.5" guiding around the zenith. Down at 30 degrees altitude about 1.0 guiding is average on a good night.? My 9.25 inch SCT is probably the most aperture local conditions will support. An 11" might be useable some of the time, but a 14" would probably be a fruitless effort for deep sky imaging. So even if I had super accurate mount, the air currents would probably bloat and distort the longer focal lengths and the cost of equipment wouldn't be worth it.?
Now if I had some Bortle 3 or less skies at some desert location with stable air, then the extra precision and investment in bigger and better equipment might be justified. And nearest dark sky site is about 4 hours away, so not a road trip that can be done on a regular basis with the larger equipment.
