Not to be a contrarian but aren't we forgetting the fact that most maglocks with a keycard or similar authentication feature require a matrix connection on some level? I'm just bringing this up as a legitimate, and quite useful, strategy is to hack whatever security measures they have set up and fool the door into letting you in.
It's not required, but it's certainly a possible route. A decker could edit the file of approved keycards to include one the PCs already have.
A key line on pg. 364 SR5 "Characters can only defeat voice recognition systems by "speaking" with the voice an approved user-by using a recording, some other simulation, or the real voice."
And here's where we learn the value of a copy editor. Contrast that sentence with, "The first step to bypassing a maglock..." (p. 363). This makes clear (well, in a "by the rules of the English language" way, not in the "this is what every reasonable reader will come away with" way), that bypassing a maglock is always a 2-step (or more) process. To consolidate my readings:
1. There's no such thing as a generic maglock. All maglocks specify the means of entry (keypad, voice recognition, etc.)
2. Assuming it's on the Matrix, all maglocks can be overcome by a decker. I'm also assuming once the rigger book is out and CCSS riggers (eqv.) get more rules, riggers will be handy here too. As it stands now, there's no practical way for a rigger to generate marks, aside from also being a decker.
3. Given that overcoming a maglock is a 2-step process, Locksmith is rolled for both these steps (pop the case, mess with the guts).
4. There are pieces of gear that replace the 2-step process for groups without a Locksmith who do their legwork. Walking up to a voice authenticator and using a recording is a one-step process, obviously, and exists outside of the rules I cited from page 363. Sequencers are sort of an exception here since they require step one (pop the case). If you're already rolling Locksmith to pop the case, there's no point to having the sequencer. If you're the "shoot the case off" type, then a sequencer makes sense.
5. I expect (and barring an official ruling, will GM) that shooting off the case with anti-tamper circuits will automatically trigger the alarm.
6. Locksmith is very handy, but by no means a cure-all. The three guards standing next to the door will probably notice if you pop open the case and start messing with the wires. Legwork, people! Find a disgruntled ex-employee, buy him dinner, find out about the types of locks used.