my very first lock was a brinks 472-42051 which is chock full of spools. this was my first lock simply because it was the only padlock i had laying around the house. next i bought a master no. 3 and a master no. 140. the 140 wasn't too difficult and took me about 10 mins to figure out, but the no. 3 was my arch nemesis and withstood my constant barrage for 3 days. i felt like a complete idiot. at the time i had a really hard time staying on the pins and relied solely on my notched lifter. it's not as deep as a medium hook but the profile is much thicker which is why i was having such a rough time. after forcing myself to use my medium hook and once i learned how to stay on the pin things where alot easier. although, i had to relearn how to pop the brinks because just the presence of the lifter in the lock, due to the profile, put the lock into a false set (the bitting's something like 1, 9, 2, 2) making it easier to pop and giving me false confidence in my ability which led to be getting really frustrated with the no. 3.
so yea, just because the lock is considered to be an "easy" lock doesn't mean that it won't fight you tooth and nail.