YYZ...
Your 1.40 on the 303/M3 is 30 mins shorter than my slog up the A303. It's fine - you just have to be realistic in your expectations and maybe scope out those places to crash at LHR when you end up with one of the really early reports, or a stray day trip between tours. As for blind lines, I can count on one hand the months I have failed to get a trip line in my 3 and a half years on the Airbus. They might not be the perfect line, but at least you can plan around them. eMaestro, the BALPA forum and Fleetlist all make swapping trips around quite feasible.
Drop me a line if you'd like any further info.