Overall, I am very happy with my Sidekick. It has many features that I've never had in a handheld device before. Many of the limitations that I have found are compared to a full featured desktop with a wired internet connection.
The Sidekick is well laid out. The flip screen is amazing when it swivels up revealing a hidden keyboard. The trackball is responsive and easy to control. The buttons on the outside allow me to navigate all the menus and perform any task that doesn't require typing without opening the flip top. The cramped layout and small buttons do make my thumbs tired after a short time. Battery life seems to be about three to four days on charge. Good enough to get me through a long weekend away from home.
Despite the cramped keyboard, the sidekick is still largish. Unlike my last palm pilot, it fits comfortably in my front pants pocket. Unlike my last cellphone (a smallish flip phone), it doesn't fit in the same pocket with my wallet or the same pocket as my keys. The best thing about the Sidekick in my pocket: the outside buttons get disabled after a short time. My previous phone's buttons where forever getting pressed in the pocket putting the phone into weird modes such as "silent". After a minute of activity the outside buttons on the Sidekick stop responding until the top is opened or a two key chord is pressed.
Things seem to be generally well laid out and intuitive to me. I'm a little confused about what the differences between "enter" (press down on the trackball) and "Done" (button below the trackball) are. I'm often pressing the OK button when I should have pressed enter. The other thing that I found odd at first was navigating the circular menu. My inclination was to mirror that circular motion with the trackball. When you move the trackball in a semicircle like the menu moves, it doesn't work the menu correctly. Instead you have to move the trackball straight up and down to navigate the menu. Moving the trackball to the left at all goes to the parent menu.
The sidekick works very well as a phone. The voice quality is much better than my previous phone (LG phone with Verizon service). The favorites menu is easily accessible for calling family and close friends. I do miss the voice-dial features I used to have. The sidekick does not allow you to record names and speak to dial. T-Mobiles myFaves plan did bite me. I got the phone number wrong for on of my five faves. I can't change the wrong phone number in my favorites for a month.
The Sidekick came with a working tmail account set up. I was immediately able to receive mail. It even has settings to set the "From" address to my normal account so that people will respond to my normal email account. I was a bit stymied by the email client's primitive IMAP support. I wanted it to point to my IMAP server and view the messages as laid out in folders on the server. Instead I could only make it copy new messages from the inbox on the server to some folder on the phone. I ended up implementing a bunch of procmail rules on the server to forward important messages to the tmail account so that I can view them on my phone.
Having IM on my phone is just plain awesome. The sidekick supports AOL, MSN, and Yahoo IM accounts. Retrieving a IM is too many steps. When you get an IM, you have to go to the main menu, select IM, select the protocol, scroll to the flashing buddy, then open the message. I would expect something new messages to be available directly from the IM sub-menu rather than having to go through the accounts and buddies. I'm used to the Pidgin instant messenger client on my desktop, it can make new messages flash in the system tray for easy access.
Pidgin also intermixes the buddies in your various accounts. The Sidekick segregates your buddies by service. You are limited to one account with any service. I would like to be able to sign on to my ICQ account (same protocol as AOL's AIM) and my second AIM account. Again, Pidgin does this right by allowing you to sign into as many accounts as you want, and logging each on in according to the correct protocol.
The IM client on the Sidekick does not log messages or store any history. I find it especially helpful to see the last few messages I've exchanged with somebody. On the desktop I also log all my conversations that I can later search them.
I like the auto-reconnect feature of the AIM client. However the sidekick lacks auto-reconnect for MSN and Yahoo. My MSN and Yahoo accounts generally get kicked offline every hour or so and I have to manually reconnect them.
The keyboard makes texting a joy on the Sidekick. I never sent text messages from my old phone because they were so hard to type.
With all the messaging ability on the Sidekick, I'm not sure that it makes sense to have three top level menu items for messaging. Text messaging and instant messaging are especially so similar, that it would be nice if they were combined into a more cohesive unit. If email could also be squeezed in there, I think it could make the top level menu a bit clean easier to use. I'm thinking of Messaging -> ( New Messages | Archive | Compose ) type of hierarchy.
The address book supports all the fields that I want. The address book is well integrated with the phone and email. Syncing ability seems poor though. I can email out the contacts in vcard format one at a time. There is no way to be a way to email out multiple contacts at once. If I send an email to the Sidekick, the attached vcard does not get imported into the address book.
I would expect a mobile phone to support WAP pages that are meant for small screens. Visiting a WML page shows the source code. The page is not rendered.
The photo album seems pretty nice. I was able to email pictures to the phone and put them in the photo album. Space is very limited with only about 2MB available for photo storage. The photo album is nice, but it is hard to switch between the album and full screen. I would expect either the "enter" or "Done" button to switch to full screen when a photo is selected in the album. The "enter" button checks the photo, and the "done" button acts more like "cancel" and returns to the menu. Instead you have to hit the top right button or use the menu. When returning from full screen to the album, the selection reverts to the first photo in the album. I would expect the photo you were viewing full screen to be selected.
I shelled out $10 for the terminal application. I'm really excited to have ssh access to work and personal servers from my cell phone. The wireless connection's high latency makes typing rather slow on a remote server, but good enough for a quick edit or an emergency. I can configure all my servers and offers to remember user names and passwords. If I don't want it to remember passwords it always remembers just the user name.
Maybe I'm missing it, there is no way to sync the calendar with my desktop calendar. Without that, I don't think I want to even try using the calendar.