Hi Steve,
I am glad my 14" scope was up for the challenge
!!
As you could appreciate this target makes the list of "tough objects I want to observe" each and every year at Ozsky, which I have been doing for over 10 years. Consequently, I have observed it a lot of times from Coonabarabran (and a few other good sites) over the past 10 years. I have observed it on a couple of occasions in my 14" scope, many times in the 18" scopes, the 25" scopes and the 30" scope. I have never tried to observe it in anything smaller than my 14" scope although I am guessing my 10" scope, which also has a great mirror in it, might do it under good skies.
Even in the larger scopes I don't get much extra detail from it, other than the brighter central bulge becomes a bit more extended. Pumping up the power to around 300X to 350X helps improve contrast and also helps to extend the central bulge a little.
Cheers,
John B