From my experience: No wall mount has ever fallen off in any way, the only way I could see one falling is if it wasen't mounted properly. Only once has a ceiling mount fallen(the one I still use), all I did was redrill and remount while also adding some wood adhesive to the screws, but it is still unlikely to fall unless you didn't mount it properly and the one I have now hasen't fallen in 2 years w a 125lb bag hanging from it. I do only recommend that you only use a ceiling mount if the rafters are exposed. You can also reinforce the wall mount by mounting 2 2x4's to the studs parallel to each other then mount the wall mount to that.
It all comes down to either spending no more than $400 on a mount and bag and very unlikely have to remount if it comes down versus spending 1K-3k on a combo set that imo most are crap.
"What the mind can conceive, the body can achieve."