There's MOLLE LBVs too (ie., chest rigs or vests with MOLLE, which do not carry armor).
MOLLE is superior in that it lets you configure what pouches you'll carry and where they're located. Some LBVs are also specialized, such as riverine vests which incorporate flotation devices.
As for "Ideal" setups, it varies not only on individuals but also on what they want to accomplish. On most days I favor a PACA low profile armor with a plate carrier, it's very comfortable and light and nimble, but it severely limits how much MOLLE real estate I have. Using a similar setup with an RRV instead is a bit bulkier but allows me to carry a lot more pouches. A full armor system like the EPC+commurbund (or CIRAS) or my FSBE AAV provides a ton of MOLLE space, but are a lot bulkier.