Yes, cylindrical locks are THE standard in the US for most applications. This started because of Walter Schlage designing the first cylindrical lock around the 1920s.
Now the reason this type of lock became so popular is simple. A mortise lock requires an individual to drill the center of the door, and chisel out most of the wood to fit an 8" tall by 1" wide lock into the middle of the door.
Where as a cylindrical lock requires drilling a 2 1/8" hole and mortising out an area for the spring latch. Now which do you think was easier with heavy corded tools of the 1920s?
Now, in terms of picking them, they're all the same. They still use pin tumbler mechanisms. The difference being a tailpiece. Thats all. A company called Lori makes something called a Lori Deadbolt which uses Mortise cylinders for their applications. Maybe you can get a hold of those and use them on your mortise lock stands for practice.
-Dave.
Never underestimate the half-diamond.