Great lock boxes. People have rummaged thru my Jeep twice now, and they don't even try to get into my Tuffy storage products. The locks are inexpensive, so you can get them all keyed alike, which is very nice. I haven't put speakers in mine (yet) but I'd have no worries they'd get stolen.
The instructions suggest that you run the mounting bolts up thru the tub so the nuts are inside the box for security... this makes the bolts stick way up into the boxes unless you cut the bolt to length first
If you leave your wheel-well liner in, I'd say run them the other way so only the head of the bolt is in the way.
I should also mention that although they do sit slightly higher than the tub, I have no problem running a Bestop duster with them in place... though you've got to remove the duster to get in them.