That's true, but really group C is almost always fine anyways. I've only rarely been unable to snag a window seat (my preference) even in C group. But you are d

That's true, but really group C is almost always fine anyways. I've only rarely been unable to snag a window seat (my preference) even in C group. But you are definitely right that you have to check in the millisecond it becomes available to get into B. A is just impossible to get unless you pay $15 for early bird check in (which I only do if it's an early flight or I know I'll be busy during check in time, since early bird is also automatic).