The only time I didn't care for our Air Canada (regular) flight out of 6 flights is when we opted to fly to Montreal, then to Paris, as opposed to our usual habit of flying Halifax to Heathrow. Why? The planes from Montreal were bigger and a 3-4-3 layout, vs the smaller 2-3-2 from Halifax...so instead of having the window and aisle for me and hubby, we had a window and middle, with someone on the end and much less room. Not to mention the extra time spent flying west, then waiting 3-4 hrs at the airport in Mtl, then flying east again. Honestly, after that, I'll stick with flying to Heathrow and connecting there, or catching a train.
Otherwise, all our flights to Europe have been pretty good with AC (and even the Paris one wasn't intolerable). Nothing special, nothing horrible...I'm just happy to be going on holiday!