Well...
Phantom Hourglass is a top-down adventure game that's almost entirely controlled by the touchscreen. Link's movements and such are controlled by placing the stylus on a point and leading Link in that direction. Sword swipes are preformed by sliding the stylu across the screen while other actions are done by drawing lines or tapping the screen. While this may sound clumsy, actually plays quite nicely and feels naturally once you get used to it. For a DS game, this game is detailed. While most other DS games are short, PH will take you a while to complete. There's quite a few locations to visit and plenty of sidequests to break away from the main plot. Some of the game's dungeons are a tad linear, but you'll never feel like you're being led through the games. The bosses are huge and very nicely designed, using the items you've obtained to defeat them in classic Zelda style. Being a big fan of the Zelda series, this game was WONDERFUL. I'm fairly positive that even people who aren't fans of the series will fall in love with the compelling storyline and intense action. To me this one of the best reasons to own a DS, it uses every feature of he DS and it does it nicely, it never feels tacked on. So in conclusion, Phantom Hourglass is a great game for fans of the series as well as a game that even non-Zelda fans should be able to enjoy, so yes, you should certainly consider it!
(PS. Sorry for spelling mistakes.) Oh, and of course Linebeck adds a great amount to the game, he's just a wonderful character and addtion to the series.