From what I remember from owning a SK 2/3 for a few years..
- The keyboards on there are outstanding. They're very comfortable to type on and mine were always very responsive.
- On the cost side of things, the data plan was definitely cheaper. I think T-Mobile may have raised the prices now, but when I owned my SK it was 19.99 for unlimited data + unlimited messaging.
- I also liked the browser on the SK better, but things did take longer to load as they were loaded closer to what can be seen on desktop computers.
- Ease of use - The Sidekick is really a great dumbphone (or has it moved up to smartphone these days, I have no idea). It's very easy to use and not as complicated as BBs. I tend to be able to teach myself how to use a device within a few hours of getting it so this was not a huge plus for me, but it's one I see people tossing out there frequently when talking about SKs.
- The free backup of info on Danger's servers was awesome. If my phone ever spontaneously deleted everything, I just had to pull the battery and all of it would come rushing back over the super speedy time of an hour. But it was very priceless to have photos, contacts, emails, notes, calendars, tasks, etc. to be saved on the servers, and Danger/T-Mobile had (at my time, it probably looks the same now) a great UI to do that on.
- Built in messengers. I never used any but AIM and Yahoo!, but they were also a desktop-like experience. I'm a big fan of JiveTalk, but I seriously miss my Sidekick AIM program. Mobile AIM from RIM just doesn't cut it and they could take some notes from Danger on their messaging apps, IMO.
On the down side...
- Battery life was good for a while and then after about six months with each device, it began to take a nosedive. Of course, I wasn't savvy enough to know then that you could pop out the battery for a new one, but battery life was still worse than it should have been.
- Signal strength was TERRIBLE. I cannot even begin to count the times that I watched my phone go into "two dot death" - meaning it couldn't receive or send data outside of SMS and most incoming voice calls went straight to voicemail. When Danger had its serious problems with their servers that also resulted in screwing up AIM, this was a serious, serious issue. Also, I barely had signal while others around me would have great signal.
- Phones are kind of clunky. I know they have slimmed down recently, but it was a pain to flip open the screen to use the keyboard. And yes, I know that's the whole big draw of Sidekicks, but it gets to be a pain if you are trying to do something surreptitiously.
- Along those lines, if you didn't have a number in your phonebook, you had to open the phone to dial it. No touch screens there - and I am pretty serious when I say that if Danger/Sharp came out with a touchscreen SK, it might be enough to lure me back. Maybe.
- Locked system. It's a serious PITA and a serious drain on your bank account when EVERYTHING you want to put on your phone HAS to come from T-Mobile downloaded OTA - ringtones, apps, games, you name it. Sure, there are some free things.. like a calculator... but I love BBs for the ability to put whatever I want on the phone when I want and be able to shop around for price. Or just slap a lot of free stuff on there!
- And when I say locked, I mean LOCKED. There is no unlocking this phone to use on another carrier. It's T-Mobile or the highway.
- Camera was ABYSMAL. I mean, seriously. It was a big step for SKs when they got a 1 MP camera while other phones were moving past 3 MP, and the camera still sucked. It turned everything a funky green color if you used the flash, and your face was frequently contrasted out of the picture. If I can find some SK pics I have left on my computer, I can post some for comparison if you're curious. Even the worst BB cams are better than the SK cameras I remember.
I know I have a lot to say on the negative side of the SK series, but they are still good devices. I really loved my SKs when I had them, but now I feel like I've personally moved onto bigger and better. SKs aren't for everyone, and they are generally cheaper than owning a BB - mostly because T-Mobile is a cheaper carrier to begin with. They also tend to be stereotyped for a younger crowd, though I have to say my mom had serious Sidekick envy when I had mine (she had a RAZR and has now seen the light and has a 8330).
Anyway, I think I've posted a long enough essay for now, but if you have any other questions, feel free to ask.
