Motorola’s Rokr is a stinkr, according to Mobile Tracker.

“One of the first things I noticed about the ROKR E1 was that it is very slow when iTunes is playing music. This holds true if you’re inside iTunes or if it is hidden. For a phone with music features being so central, this is a fatal flaw. My unit couln’t even keep the play time counter working smoothly (see video). When iTunes is playing a song menus are also slow and I easily typed faster than it could keep up with. Navigating through menus is also painful–count on a second or two after you touch a button for it to respond.

… I’m happy to report some good news though, the speakers on the ROKR E1 sound amazing. Great quality and even bass (it has a bit of rumble when you hold it). Everyone I showed the E1 off to was impressed by the built-in speakers. The idea of stereo speakers on a device this small should be ridiculous, but they sound great. Of course you’ll run through the battery faster using the speakers, but this is one thing that even the iPod cannot do.”