The optical formulas are identical except for the possibility of coatings though I believe that the vast majority of later orange tube had XLT coatings, but I cannot say with certainty that all did. XLT scopes have a sticker that says XLT, and the previous generation scopes had a sticker that said "Starbright."
There may be some small differences in accessories, trim, mounting holes and such. For example, the mechanism for attaching corrector covers has differed from time to time.
Otherwise, it will perform more or less exactly the same as any standard C8 with optical coatings with the quality of the specific samples being compared the only meaningful variable.
(The XLT optics also use a different glass in the corrector, but again, that is a difference between XLT and previous coatings packages.)
Edited by Eddgie, 13 November 2019 - 11:36 AM.