There are plenty of well-publicized gripes with the iPhone. A slow mobile data network, tricky keyboard, no MMS, etc. The list goes on. None of the big spec-related weaknesses have proven to be dealbreakers for me yet as I've been using the iPhone this week (I'm trying to defer to the iPhone instead of my home PC, stereo, television and pretty much any other gadget to test its convergence abilities accordingly).
In a device billed to be all about its revolutionary user interface software, with even the tiniest of details carefully though-out in true Apple fashion for ease of use, it's logical to assume that the phone's most painful shortcomings will also be revealed in the smaller details.
Case-in-point: when I first plugged in the iPhone to my home computer after its initial sync, its music tracks were grayed-out in iTunes. I thought this may have had to do with using a different computer from the one I used to activate the phone, but alas, after a bit more research, it turns out this is default behavior. Not only can you not play songs on your iPhone via iTunes, but you also cannot manually drag-and-drop media files for loading into its memory like every other iPod. You can only sync the iPhone with a playlist or library on a single computer.
So if you use more than one computer to listen to and organize your music, you're out of luck—the only way to load music onto the iPhone is to have it mirror an iTunes playlist on your computer track-for-track. Any songs on your iPhone that aren't on the computer you're syncing with are deleted.
I keep different music collections on my computers at work and at home. With my dusty old black-and-white iPod I can simply plug in at work and load an album I may not have at home without erasing the songs that only live on my home computer. But with the iPhone, I have to choose which computer to use exclusively.
Sure, this prevents you from plugging your iPhone into all of your coworkers' computers and grabbing their music without paying for it (again, something all other iPods can do), but it also prevents you from loading the album you just legally purchased from the iTunes store or ripped from one of the CDs you keep at work for your trip home.
So buried beneath the legitimately great touch interface, a larger screen and snazzy Cover Flow browser lies a limitation that could be minor to some, but fairly significant to others. If Apple is serious about a DRM-free future, why the uncharacteristically paranoid feature crippling? Let's hope this gets hacked (or updated) soon. —John Mahoney
Link - "help manually managing music" - Apple Support Discussion Forums