Moving to the UK was the best thing I could have done for my career hands down. Been here 3 years in March and have had nothing short of a rocket booster strapped to my back in terms of career progression. Made it to BA, loving it and making an absolute fortune compared to my mates back in Canada (including AC an WJ). Would do it again in a heart beat no questions asked.
My advice to anyone trying to do it is this. You must give 110% from day one through until completon, including finding employmet. Do this and you will succeed. Canadian aviation experience is highly regarded here and I am pleased to say that from week to week I hear more and more voices from home on the air.
Good luck to all and never doubt its a bad move!!