Personally I like Lowrance units, and I'd love to find a used Baja for my Bronco. Compared to other modern offerings though, the current Lowrance units are weak. I probably would have bought their latest handheld if the vast majority of the new users didn't give it horrible reviews. The company was bought out several years ago, and I've not heard anything special about them since, making mediocre to plain awful units for anything but the Marine and specialty customers.
You do realize the unit you mention are Marine units, made for sonar as well? Lowrance does make off road vehicle units that are basically the same case but lack the sonar stuff. Plus are rugged for a 4x4. If you have a boat it's possible you might try using it double duty, which might make it worth a try. But if not, I wouldn't recommend dropping the cash on any of them, it's high end stuff.
I'm in a particular situation where I'm very familiar with the older Lowrance units and already have the software to load Topo maps into them, so where I might like a used Baja unit, 99% of people who "just want it to work" need to get something less specialized. For an X, Lowrance units like you are mentioning are too big, too bulky, and too specialized to do you much good. It's way overkill. But say for a dedicated wheeler, or better yet, a race buggy, sure drop it in there, you'll use it, and you'll need a rugged unit that is dust, vibration, and water resistant.
In an X you want to be comfortable in, it's going to be a big hunk of equipment in your way that only does one thing, and while it may do that one thing well, it's taking up a lot of space, time to install, time to learn to operate, for very little reward to the casual user. I'll probably go the tablet route myself once I decide my current GPS units are getting too clumsy to use. While I like devices that do one thing and do it well, in a small space like a vehicle, multi use devices become much more practical. You can easily buy a tablet and mapping software for the same money a big Lowrance will run you.
Edit to add: I do not think Lowrance units autoroute, so don't plan on using it to navigate the highways for you. Great off road, but takes a lot of attention to use for highway driving. I've done it, but rarely could I do it and drive.