Two things set the iHP-140 ahead of its competitors.
First, the fact that it acts as a USB hard drive means managing your MP3s suddenly got an order of magnitude easier. Just move your music collection permanently onto the iHP; all the powerful software you already use on your PC can already work with it, to manage, rip, burn, sort, edit, even back up your music collection in place. No need to keep two things in sync, and think of all the disk space you'll free up. No matter where you're accessing your music, from your PC, your TiVo, your car stereo, or on a walk, you have the same tracks, the same playlists, the same library, the same organization.
Second, the attention to detail on implementing the features on the iHP-140 stands head and shoulders above anything else. This was clearly designed by someone who uses it, and who would rather do it right than fast or cheap. It's in the big things -- like support for Ogg Vorbis, WMA, ASF, etc. -- and the little things -- like how the included remote control can do everything the main controls can (so every single screen has been developed twice).
There are a few things that aren't perfect. The FM tuner gets moderate reception -- in an urban area it'll be fine, in my rural area it doesn't pick much up. You can't record from the FM. You can queue up the next track, but no more than that -- though on-the-fly playlist editing is promised in a coming firmware update. There's a bit of a learning curve, since a few controls are used to do many things.
But by and large the quibbliness of the misfeatures points out how well the features are done. It looks good, it works well, and neither one is compromised by the other. If you've ever looked at another player, been irked by some arbitrary limitation in how it worked (for the sake of simplicity, probably) and thought, "if I were designing one, it'd do this instead", the iHP-140 is probably the player you were designing in your head.





