My complaints about iPod/iPhone:
1. iTunes. You MUST use it to transfer files to and from your device. I should be able to see my device as a drive letter and be able to drag files over to it. Also, iTunes is very slow and clunky. It doesn't matter what computer I'm using and how fast that computer is, iTunes just seems to hang for long periods at a time. You also have to be careful about having iTunes installed on different computers because moving files to and from an iPod or iPhone is done by synchronizing in iTunes. If some files are on one computer and not another, you could actually wipe files off of your iTunes or iPod when you go to do a synch.
2. The iPod doesn't have a microphone. This is particularly annoying on the iPod touch. The Touch can use all the same programs as an iPhone, as it's essentially an iPhone without a phone, but because there is no microphone, you can't use certain applications that utilize voice recognition and you can do voice recording. Get with it Apple. Zune HD has a mic. Even Creative Zen has a mic.
3. Titles of movies and songs don't scroll. This is true even with the Touch and iPhone and is amazingly frustrating. So if I have something with a long title... say an MP3 with the artist name and song title or a TV program that has the season number, episode number, show name and episode name in the title... you can only read the first few characters of this title if it's longer than what the iPod or iPhone screen allows for. Dumb.
4. Inability to multi-task. There's no pausing a game on your iPod Touch or iPhone so you can read an email or check on your stocks. Once you leave that game, you have to restart it when you fire it back up again.
5. Battery life is horrible. Of course, this is a relative thing and the battery in an iPod and iPhone are quite small. Regardless, I feel this is still something that Apple should address. The fact that the battery can't be (easily) accessed and replaced only doubles this problem. With other companies' phones and MP3 players, spare batteries can be swapped out if need be when you're running out of juice.
6. There's no stop. Only pause. It sounds like a silly complaint, and on the surface it doesn't sound like a big deal. But use an iPod or iPhone for a while and you start to wonder why they didn't put a stop button that allows you to stop playing a song or a video and either replay that file or go back to browse for another.
7. There's flaky WiFi on the Touch and iPhone. I'm not sure why, but if the device is allowed to fade to a black screen, I will lose my WiFi connection and it takes it forever to make the connection again.
8. Lack of non-proprietary connector. I know WHY the iPod has a proprietary connector. It's because you can actually control an iPod or iPhone through it's interface. Simple signals through the multi-pin connector can control track navigation, volume, etc. There's even a video output pin. But this is no excuse for a complete lack of a standard connector like a mini-USB. Charging the iPod or iPhone is impossible without having an expensive, proprietary iPod cable.
9. Spell check. Yes. Spell check on the iPod Touch and iPhone will drive you mad. Unlike most phones that give you spelling correction suggestions, Apple just automatically assumes you're a crappy speller and changes words for you on the fly. You have to tell it NOT to change words for you as you type, which I feel is completely backwards behavior. Let me keep typing. If I want to change the spelling of something I think I might have spelled wrong, I'll tell you.