In my opinion, a stack-on cabinet bolted in is better than a safe unbolted.
I disagree, those cabinets are no heavier than the material a standard rolling tool cabinet is made from and have a cheesy locking system. Anyone with a crowbar could get in one of those cabinets, they really were not designed to prevent theft. They will however keep little fingers away from your guns provided you keep the keys on you and that's about the only thing they will do. It would probably take all of about 3 minutes to open one of those doors with a crow bar. I have one of the stack on cabinets and I think when I upgrade to an actual safe I'll grab a crowbar and see how long that locking system lasts. I'll make sure I post the results for anyone interested.