Rod,
They are always tougher in a SCT. Due to the number of optical surfaces inherent in the design ie Corrector Plate, Primary, Secondary, Star Diagonal and also the size of the central obstruction you will not have the same light transmission as a Newtonian or a refractor. Not a great difference but definately down a couple of percent which can matter when your talking borderline objects.
All is not lost
You just need to get things in your favour.
High Altitude (hence less air to look through)
Good transparency
The correct magnification is important. In your 10" scope somewhere between 120X and 180X should be the zone. Your 16mm Nagler T2 should be fine. I will help you in seeing them next time Orion is well placed and we are together, if the 16mm Nag isn't fine I will lend you my 20mm Pentax XW.
CS-John B