Practical Sailor had a great test of chargers , if thats what you need.
For most folks that cruise (the M&M are different) purchasing a smart stand alone charger doesnt make a lot of sense at $200 to $300.
An inverter is useful on most boats , and since the guts are basically the same, an inverter with charger might be less expensive than 2 units.
If I were cruising an out of the way place , south to Panama , I would go with 2 units tho.
FF