Coma for me in my 10 "

was never an issue with a 13mm or 7mm nagler
On nights of average to poor seeing the 7 mm was sometimes a little to much power..At low power my 27 panoptic is a fantastic eyepiece that gives pinpoint stars over nearlly all of the fov .. A while back I happened to purchase a 28 mm pretoria eyepiece which corrects for coma at f 4 I think..this is one likeable piece of glass..even at f 5 its pinpoint views right to the edge ..so stupidly I now have 2 low power eyepieces that are both great
As suggested I'd look through your scope before shelling out for a CC
my recollection of a 5 " view of omeg cent compared to the 10" is just
more than a little differant coma or not