Yeah, viewing this on a tablet would be awesome! Actually, for tablet users, I can imagine the text in lots of angles adds something. I'm thinking… If you were to make a game for ipads and such, you'd take advantage of the differences in how one use a tablet compared to a computer, with the touch screen, gyro, etc… So images can be made with the same idea, right? Maybe this is a map for tablet viewing?

Of course, you could also make a computer port of it, to continue the simile… And in that case, I would personally change all the text. I like how it follows the graticule, and I definitely think you should keep that, but those that are the most upside-down could be flipped. That's what I would do at least, but hey, it's your map and if you like the labels the way they are, keep them!