I ride both depending what day it is etc, typical summer week looked like this:
Monday – Road tour with club as part of a sprint championship (~15ppl)
Tuesday – Cheeky MTB session on my own for a hour or 2
Wednesday – Weekly general road tour with (~15ppl)
Thursday – Mtb ride out with Mr B for an hour
Friday – MTB solo session for a couple of hours
Sat & Sun – DH with mates at our bike park one day and normally the other day is a rest day unless I'm racing etc.
So just depends what on etc, enjoy both although not keen on bif MTB groups as it always seems like you spend a lot of time waiting around etc.
Winter is very different, solo night rides all week followed by a group road or MTB ride out Sat and Sun plus spinning one night a week from Nov till Feb