I laughed my pants off in recognition of what fredpuli said! It is so true. Everyone else's descriptions are spot-on too.
Jack, our BC, is coming up 4, and he has been hard work! Creative, intelligent, with boundless energy. I don't think your circumstances are unsuitable, as long as you are willing to accept that a mad dash round the garden isn't sufficient stimulation for a Collie: it will need a minimum hour-and-a-half each day. EVERY day! If Jack doesn't get his big walk, he bounces off the walls! Be prepared to invest in lots of "puzzle" toys, like treat balls that the dog has to work to get the reward from.
I don't have anything to add to the rest really, except that I love Jack to bits, and wouldn't be without him. He is my absolute soulmate!
I appreciate that you have thought hard about this, and asked people's advice. I see you are looking at deciding against it for now, but I can promise you that on the whole, if their (extensive!) needs are met, they are a joy to own, and a pleasure to be with.
I never knew what a one-person dog Jack was 'til my partner came off night shift. Jack's had a really hard time adjusting, because he is so used to having the majority of his day with one or the other of us, but not both. So that is another consideration.
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