Although the unit is factory unlocked that I got from eBay, it works fine with AT&T on both GSM and 3G frequencies. I can even see it sometimes use HSPA+.
The unit still has no physical qwerty keyboard which I hate the most with my iPhone 4. However, I realized if the screen is large enough, I can reduce the fat finger situation. This Samsung Galaxy S2 have a 4.3 inch but thinner and lighter that fits perfect in my pocket.
Some info I'd like to share that I feel not available from iPhone:
Music library on iTunes
I like the idea of being able to sync the iTunes playlists via wifi. I found iSyncr app that can transfer the playlists to the SGS2 both via USB and WiFi. There is also DoubleTwist Air app. I have not tested both fully yet but so far I like the iSyncr.
File Management via WiFi
I like the idea of managing the phone without connecting it via USB wire. The SGS2 supports file management via wifi called Kies Air. This is bundled app so no need to download. You can upload/download your media (pics, videos, documents, etc).
Applications Store
I like the idea of not being restricted to just one app store. With iPhone, felt restricted to iTunes. On android, I found out that you can purchase applications not just from Android Market. There are better alternatives like the Amazon Appstore. You can also download .apk files and then install them on your android phone. You just need to enable third party
Widgets
Did you know you can have an application running on your screen without the need to execute it? Other's may have different explanation about widgets but that's how I can describe as its benefit.
To give an example, I'm a calendar person since I started using the Palm/HP handhelds. With that said, I find the built-in stock agenda widget very helpful. It takes up one whole home screen and you scroll up/down through your appointments. This is as close I can get to the cards view of Palm/HP WebOS. If only there's a facebook widget that takes the whole screen, that's another great widget.
To add widget, simply press the chosen home screen for a few seconds. Afterwards, select Widgets from the "Add to Home" popup menu to choose your widget.
Terminate Application
I like the idea of being able to terminate an application. The SGS2 can do more than that. It can even clean the memory. You can do this with the SGS2 by running the task manager.
Storage
I like the idea of being able to increase storage without replacing your phone. The Samsung Galaxy S2 have an microSDHC slot next to the battery. I purchased a 32Gig Sandisk. I place my music on that storage while apps are on the internal 16Gig memory.
Replacement Battery
I like the idea of being able to easily replace the battery without breaking the warranty.
Did you know that rechargeable batteries starts to loose their quality after a year? I use to have an iPhone 3GS before the iPhone 4. The battery on that 3GS only lasted just barely over 1 year. Replacing the battery requires surgical operation and you may end up paying more rather than just grabbing a replacement battery from the store.
Notifications
I like the idea of getting notifications on the single area of the screen without interrupting what I'm doing. That is a true multitasking experience. I guess this is the feature Apple will try to address on their next release. This feature is already available on Android.
Screen Quality
This thing is very nice.
To give example, the pictures from my Flickr look far better than on SGS2 as compared to iPhone 4. The samething for the facebook pictures.
Video Quality
This can record up to 1084p video.
Camera Quality
This has 8 megapixel camera at the back and 2 megapixel in front.
Hardware Quality
This is thinner and lighter than iPhone 4 considering the SGS2 is even a 1.2Ghz dual-core processor. The iPhone 4 is only 1Ghz single core.
Some small hiccups on the transition:
Email application
The stock email client works fine but based from my research, the K9 is far better. This is free downloadable from Android Market or Amazon Appstore
Visual Voicemail
I lost the visual voicemail I liked with AT&T + iPhone. However, a better alternative I found is Google Voice. Did you know that this google voice can transcribe you voicemail? Yup, read your voicemail rather than listen to them. But they must leave it in english though. That's alright.
IM stock application
The instant messenger appears to be not working with this international version. It spits a "Error occured" error message when adding account. Forums indicates its because its country specific. However, the default Gtalk works fine. There are also other alternatives like Meebo or BeeJive that have push capability.
MMS issue
I cannot send an MMS if the destination phone number has special characters like 1 (234) 5678901. Found a forum that I need to remove the brackets to make it work. e.g. 12345678901. Possibly a compatibility issue with AT&T since the phone is factory unlock.
Amazon MP3
The amazon mp3 app defaults to amazon.co.uk. Found a forum that the default system language setting is English (UK). Simply change the system language setting the language to English(US) fixes the issue.
