I owned an older Garmin 168s, and I've used numerous other Garmin marine devices. I'm very frustrated with the 541 because it can no longer provide some very simple, but important information on a single screen. In previous versions, a user could select the number of data fields, size of data fields, and content of data fields. The data bars on the chart and compass screens of the 541 are no longer freely selectable. Rather, the data bar information is grouped into pre-programmed categories with very limited select-ability. As a sailor, I need three simple things on an uncluttered chart view: VMG, bearing to next, and depth. It's unavailable with the current 541s software, but supported on many earlier versions of Garmin marine products. Sure, the 541 can display all kinds of fancy things from external devices, but simple GPS functions are now thrown aside with neglect. I see it as a step backwards, and I sure hope Garmin invests in a software upgrade to fix the bugs!
Another gripe is that Garmin has removed the "quit" button. That vastly increases the number of button pushes needed to navigate the screens, and greatly increases the amount of time fiddling. Unfortunately, a new button can't be fixed with a software upgrade.
I don't know if it's going to be an issue, but the manual doesn't say anything about how one would update the base maps. I speculate that Garmin wants users to buy the enhanced map products to keep the device up to date. I'm reminded that when my 168s died, Garmin said it's not possible to transfer the map products that I purchased for the 168s to another (used) 168s...my investment in maps was lost. I sure hope this won't be a repeat of that business model!
I'd give this thing 1 star because it does basically work, but I will say Garmin has improved the receiver sensitivity and device speed over my older 168s. I suppose they deserve a second star for that...