You could look at it another way, that if you have a similar issue arise, you have someone nearby that could get you into the apartment without having to bust it down. Same with your daughters, maybe they'd be locked out and need to get in.
Actually, wouldn't the apartment itself have a set of keys to get in? Considering the amount of landlords being caught entering tenants places (without proper notice, and some of them were doing all sorts of crazy shit, stealing, putting in video equipment, think one was caught taking women into their tenant's bedroom and having sex with them), I'd probably be more worried about that.
Guess it'd depend, as there's also stories of sleazy locksmiths (wasn't it NYC where it was known to not to call locksmiths - basically you want to just deal with it and go during business hours and just say you'd like to get locks changed - as there were a lot of instances where they'd send someone out, and then say it was like obscenely higher price, and they'd pretty much outright threaten that if you don't pony up that well they have the keys and know where you live).