After a few days I love what the Pre could be with some work on Palm's part, but I'm starting to notice a few major os flaws (hopefully they get addressed quickly).
Primarily the alarm clock is really unreliable, which would make me think twice about getting one if I hadn't already. I woke up late today to find my phone asking me to dismiss the alarm, which wasn't actually ringing. The sound was at full volume, so it's not because I'd set it to silent, or vibrate. I've also found that sometimes in the evening the alarm has cancelled itself for the next day and I have to reset it. You also have to set it at 5 minute intervals, which is a little annoying (yes, on some days I really do like those extra 2 minutes of sleep, but can't afford the full 5)
I've had a few launcher issues as well where it will just open up the last application instead of the launch menu. So far this has fixed itself after a few minutes, but I can see some resets in the future (and the Pre takes ages to start/shutdown).
There's no easy way to manage files, but I suspect an app will come along to fix that (I can't figure out how to delete pdf's away from a computer).
There's also a little light-bleed from the lcd around the edges of the phone, which I noticed last night watching a film, and of course the battery life really is awful.
All-in-all I still prefer the Pre over my old samsung (which was stuck on the old EDGE network and quite battered), but it still has a couple of major kinks that need ironing out.
Edit: Now I'm testing it, the alarm won't sound at all! ffs
Edit 2: Got it working again, and having looked into it, it seems that until they bring out the update the pre won't play daily alarms that you set on the same day :/
