DUKE OF MT. DEER was never meant to be a straight wuxia novel like the CONDOR HEROES TRILOGY, STATE OF DIVINITY, or even DEMIGODS & SEMIDEVILS. It was a satiric look at the whole wuxia genre, and a hilarious one at that. For these reasons, DUKE OF MT DEER, taken for what it is, is considered one of Jin Yong's finest works. Some even consider it his best work.
If one tries to take DOMD as straight wuxia, however, isn't it pretty much terrible? Both the wu and the xia in DOMD are pretty underwhelming (although intentionally so). Even the more straightforward wuxia stories have moments of effective comic relief to balance them out, but in the moments that DOMD tries to be more serious, it just doesn't quite succeed. One still feels like one is following a comedy rather than a wuxia story.