Jim, look at it thisaway...
...with a charger, you have to run shore power to a breaker box with breakers of course. From there to the charger and other 110vac circuits. from the charger to the battery to a fuse block to your 12 vdc circuits...you may wish(need) to add various switches for switching the various parts in and out of the system as well.
With a converter you run 120vac into one side, run battery power into the other side and the wiring for both 120vac and 12vdc outlets/appliances into the back..any switching is done by the internal circuitry of the conveter...EVERYTHING goes into one place for a much neater/simpler install.
For the novice, a converter is probably the better way to go. The pricing of a WFCO(12A) versus a Deltrans(5A) and its component setup are very close to each other.
The only real advatage to using the Deltrans setup is that it is "componentized", meaning that if a single item goes bad, you only haveta replace that item...however the WFCO and the Deltrans are both designed to give lots of duty inna fairly rugged environment...there is also the "geek" factor of doing it yourself for the Deltrans to consider.....
madjack
...I have come to believe that, conflict resolution, through violence, is never acceptable.....................mj