Maybe you’d better ask your question on a Garmin-related forum.
OpenStreetMap is only a database for geographic information, and it is up to map makers like the ones in your list to decide which information to shown. I guess Garmin Openfietsmap Full is the largest because it shows more cycling-related information from the OSM database on their maps than Garmin Openfietsmap Lite.
It means it has the most data in it. Whether that extra data is something that is useful to you depends on what the the map creator has put there and what you are expecting to see, because with any map (not just those for Garmin devices) there’s a trade-off between “how much can be shown that is useful” and “showing so much that the user cannot work out what is what”.
The answer is likely actually “none of them”, in that from what I can see it’s their own map style, and is not trying to show the same sort of data as any of the six web maps at osm.org. It is of course using OSM data, which includes much more than any one map can sensibly show.
Try and load a UTF-8 map and see if you get an error . This sounds flippant, but Garmin’s model range is so vast (and different models have had different firmware) that it’s really the only way to be sure.
(just to add a bit more not directly in answer to the question, from the point of view of someone that creates maps for Garmin devices)
There are a few things that need to be considered.
How much data should be included? Too much means that maps may be difficult to use, and a larger file size means that maps for larger areas won’t fit into the maximum map file size. Also, on older satnavs too much detail means that route calculation is slow or impossible. As an example, the OSM data that different projects use can be seen at taginfo. Here is the entry for the detailed Garmin maps I create**, and here is the simpler one (close to the mkgmap defaults).
Should QA information be shown? On the detailed maps I create if surface or smoothness tags are missing from a path or footpath that will be indicated to the user, but that’s mostly only useful to people aiming to update OSM, not people just getting from A to B.
How should routing be supported? If you’re walking or cycling, would you expect to be routed down motorway (probably not, but actually depends on region), a trunk road (probably, but again depends on region) or a path (it depends). I try and do things like "support walking on trunk roads if there is pedestrian infrastructure available (e.g. sidewalk=separate, sidewalk=both or similar), but not all maps will do this.
How should OSM features map on to the Garmin icons and search menus? This is tricky, partly because these vary between devices. Also, taking just the “Food and Drink” menu as an example, it’s all a bit “American from 40 years ago” - you get “French”, “German” but then just “Asian” for what is eaten by most of the people on the planet. I chose to ignore the American names and split eateries into sensible European categories.
How should extra information from OSM be shown? I’ve used “brackets after the name” to show this, for things like “the hiking route that goes down this street”, “the denomination of this church” and “whether this bus stop has a realtime display or printed timetable”.
Everybody creating maps for Garmin devices will have answered these questions slightly differently, and every user has slightly different expectations. That’s why answering questions like “which maps are best for me” is hard .
** and you can too - it’s essentially just a runnable shell script calling other software such as mkgmap. Currently I just create GB and Ireland maps, but if you want to try out one of the styles on a Geofabrik region, let me know.
. This sounds flippant, but Garmin’s model range is so vast (and different models have had different firmware) that it’s really the only way to be sure.