I purchased a Garmin 441s and am now having a bit of buyer's remorse. The reason has to do with the fact that I'd like to use my laptop at Nav station as primary and the chartplotter as backup. The problem arises with the Explorer charts of the Bahamas (which are generally agreed to be the best charts of the Bahamas). The 441s chartplotter comes with those charts included, but now I have no way to access them with the laptop. On the other hand, had I purchased something like the Standard Horizon you referenced, the C-map chips can be used by both the chartplotter and laptop. This allows you to buy the chips once, but use them either way. That appeals to me. Anyway, this is a vote for the Standard Horizon if you wish to use both a PC and dedicated chartplotter and share the chips between them. Here is a quote from the makers of the Explorer charts:
At this time our Explorer data is only available electronically through Nobeltec, C-Map and Garmin, but not in BSB format.
What makes the C-Map chip option unique is the ability to read them with both dedicated chartplotter and Nav software running on a PC. Note: to avail yourself of this capability you must purchase a C-map c-card reader and compatible Nav software.