I wish I could speak so glowingly of the security lines at BWI. While they have gotten better, they are not even close to DCA. IAD lines on a Saturday AM are comparable in my experience.
My biggest problem with the BWI crew is the way they handle the shoe policy. Unless they have some special intel, they are not allowed to force you to take off your shoes. I would say I have had to remove my shoes 75%+ of my trips out of BWI, and maybe 10% out of every other airport. These are standard tennis shoes, mind you, and never set off the metal detectors. I realize that they have a job to do, but I don't believe the constant shoe removal at BWI is just my luck of the draw to be traveling on those days when all shoes must come off. I will relay one more brief story, where a co-worker of mine was traveling with his girlfriend out of BWI, and was asked to remove his shoes by the woman on the other side of the metal detector. He declined, to which she replied they "would set off the metal detectors". He knew they wouldn't, so he walked through and she raised her arm into the machine and set off the detectors with her watch. He proceeded to argue with her, and his girlfriend just walked through without any type of hassle about the shoes, or even a glance at the detector. He proceeded to complain to the supervisor, but was basically told to get lost. I can understand a secondary search, but setting off the detector in an act of spite is just plain wrong.
The moral is avoid BWI.