I've always used CMR (or CMP) cable in commercial even if there are IDFs each floor and/or no vertical penetrations, for the simple fact that CMR can be used in place of CM/CMG/CMX and it costs virtually nothing more than those cables. Having to pull out CM because it was run thru one or more floors is simply not ever going to happen; I get paid to do the job once, and right.
Myoclonic, you *might* want to look up TDMM (telecom distribution method manuals) specs, tho they are way stricter than the NEC and the 2 volume set I have from 2003 is roughly 4x the pages of the 2014 NEC. They are not code but will address most any possible installation questions you may have with IP cameras concerning the wiring of them.
I can promise you if you trench in catx cable 3" down (scratched in), you will be out there in less than a year fixing cut sections. The first vehicle that drives over it or shovel pick will cut or break that 23/24ga wiring in a heartbeat. iirc, PoE cameras require at least 3 pairs to function. Splicing cat5e/6 cable is not much fun, especially underground. Simply finding the fault requires a TDR meter. A few hundred feet of 3/4" PVC conduit is relatively cheap compared to trenching, and will be about a 1000% better than free run cable at any depth. Initial cost is higher, but long term is a far better installation for the customer.
Electricians do it until it Hertz!