So, pros, misc and cons. Lets do the pros first.
1) Keyboard. Full querty, neatly implemented. Slide mechanism good.
2) Touch screen. Very nice action and easy to use. I'm already sad about having to go back to using the keypad to navigate around.
3) The PC application is actually pretty good, compared to the one for my previous phone (a sony) which kept refusing to acknowledge the presence of the phone at all.
4) Connection speed for web stuff.
5) Overall look and feel of the phone.
1) Web browser. Not bad once I got it zoomed out but nothing spectacular.
2) MP3 player. You can't just plug your regular headphones straight in, you have to use an adapter (which they give you but you do then have to carry it around). Other than that, fine.
3) Some functions require rather more menu selections than are optimal (e.g. text messaging). Still, it's usually pretty obvious what you need to do.
1) Calendar. This is the deal breaker to which I referred above. Apart from the fact that you are limited to 300 items in your schedule at any one time (annoying but I could have worked with it, I'd just have to archive things) it has a serious bug. When I transferred items from my PC to the phone, I could see things this month and things in the past, but not things that were in the future on most of the views. The events were there - you could see them in the phone editor and if you used the Event List view (annoying because it starts from the earliest event!) but not if you looked at the day, month or week view. If you edit the event on the phone it then shows up properly but I'm not going to edit all my events just to get that to happen! I rely on having my calendar on my phone so that I can arrange things with people and not end up with clashes - obviously, it might not have been such a big deal for other people.
2) Camera. Good MPs, flash, focus etc but there was a noticeable pause, of say 1sec between pressing the button and the photo being taken. This means no cute photos of kitties as they rarely are prepared to hold poses for me!
3) No SyncML. Most people won't care about this but I want my phone to automatically sync with my internet calendar etc. My old phone had this, this one doesn't. Most people don't care but for me it was annoying.
4) Samsung apparently have their own weird operating system which means that most applications created for phones aren't necessarily going to work on their phones - you have to suck it and see. I didn't realise this when I bought the phone - didn't think to ask - but it is slightly annoying. On the other hand, the main app I actually use, LJ2ME, works fine, so it wasn't particularly an issue until I was trying to find something to replace their onboard calendar software.
This sounds like I don't really like it but actually, I really do. It's only the calendar thing that's killing it for me, the other stuff is just things I've noticed that I'm not wild about but am prepared to accept in exchange for the pros, which I do love.