Before I got an iPhone, I had a GSM BlackBerry 8800 on T-Mobile. The experiences were not similar.
BlackBerry -- I use a third party sync software that does a really mediocre job of syncing contacts from my address book to my phone and back. It routinely creates double-entries of existing contacts. It's so bad at merging information that I have to use it as a one-way sync, either going only from phone to computer, or only computer to phone. When I try to do both ways at once, it constantly munges things.
iPhone -- I add or update somebody's phone or email address to my address book, and within a few minutes that contact is synced into my phone, over the air. If I do it on the phone, my address book on my computer syncs within a few minutes as well. It's all seamless.
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BlackBerry Media Player -- LOL horrible.... just completely and totally horrible. Sync was a pain in the ass. The usability bad, but the battery life was complete shit if I tried to use it for a day.
iPhone Media Player -- Works pretty well. Sync is easy. Menus are easy. I can listen to music all day, and not run out of battery.