I have been flying on the Q400 for 13 years basically since they were introduced at Flybe, granted not on a weekly basis like some commuters.
I have never had a tech cancellation or extensive delay. I am probably just very lucky but it’s like any mode of transport the more you use it the more experience you have both positive and negative. I take the train regularly to work and have more problems on that compared to my family who use it only at weekends.
The Q400 hasn’t been grounded for engine issues nor was it entirely grounded during the SAS fiasco over the gear. I think people forget that these aircraft are operating multiple sectors a day compared to some airlines with the jet - so they will be prone to more TLC.