Power wise, I would have preferred it.
However, they messed up the 15 significantly for 2 reasons
1 ) classic gain side does not have the crunch mode. It has just the clean mode and barely crunches up without volumes dimed and a high output pickup. There is no classic marshall sound here really. Great clean tone, but no marshall crunch.
2) Ultra mode is a gain mess. The gain structure is flubby, farty, fizzy, and damn near unusable past 9 o'clock on the dial.
Tube rolling helps a bit, but by trying to tame ultra, classic will get even cleaner.
Some guys over on the Marshall Forum have some mods to help out the ultra channel if you like to tinker.
I have played the combo and head and been super disappointed. Its why I bought my OR15. I now own a dsl40c which even in 20w triode shames the dsl15. In fact, the Dsl5 is voiced much better than the 15 on both channels, especially the Ultra.