Originally Posted by ZenFlyer

Fwiw, my first UR transfer to Aeroplan took 24-48 hours IIRC, but every one since then has been instantaneous. Having read of some delays, I deliberately made my first transfer a small test transfer of 1000 pts, and by the time I had an award flight ready to book, the transfer wheels were greased so to speak. My experience with United has been similar except that the first (larger) transfer took about a week. So I'm not sure that this is actually a differentiating factor between UA and AP. YMMV of course.