Hi All,
Just an update for people switching from the iPhone to SG 2, here are my observations after owning the phone for 4 days. I've now had a chance to properly play with it.
I've owned the following Smart phones Nokia e71, iPhone 3gs, HTC Desire, iPhone4 now the SG2.
GOOD POINTS
At first it felt cheap however I really like the lightness of the phone, the iPhone 4 screen now feels small. As an actual phone device it is leaps and bounds above the iPhone in my opinion, I will revaulate this over time as I still have an iPad 2 and the other half still has the Iphone 4. (IOS 5 has a lot to live up to)
Notification system is brilliant.
Gingerbread and the SG S2 fix the majority of issues I had with Android i.e. App2 to SD plus pitiful memory of the HTC desire.
The level of customisation is amazing, I installed launcher Pro from the Android market and I cannot believe how flexible it is, it makes my iPhone look like a very basic tool.
A few of the things I have customised
I now have a scrolling dock with the apps I use, I can click to open the App from the Dock but also swipe up to perform another action, an example being press the contact icon in the dock to open my contacts, if I swipe upwards on the same icon it will call voicemail.
Likewise I can have contacts I often call attached as a short cut on the homescreen.
Voice activation is also top notch and makes for great lazy browsing.
The other godsend it being able to turn bluetooth on and off from the homescreen, it drove me mad that I had to go to drill down on several menu's to do this on my iPhone 4.
Lock screen widgets are also amazing, I can change my music without having to unlock the phone first!!
Different sounds for different notifications i.e. twitter, facebook, e-mail, sms.
The other joy is being able to use websites that support flash, I could finally watch the BBC F1 website aftershow videos without having to get my laptop out.
Nearly all the apps are available on Android that I had on the iPhone, there are a few key exceptions such as TOMTOM (google Nav) is not as good but it works), App tracker (Finance Manager),
Lastly I love the PowerAmp MP3 player, it did cost me but it is the only MP3 player I have comes across that beats the iPhone one.
Battery life also appears the same as the iPhone 4 which is great, previous Android devices have suffered badly from this.
BAD POINTS
App store is no where near the iPhone App store, I don't care that Android has more free apps, most appear to be poor rip offs and clones. Where are all the major developers that are apparently developing for both?????
If you love Games do not give up your iphone, likewise general apps are not as good.
Google Nav is good but not as good as TOMTOM, CoPilot has poor routing, I paid for navigon ages ago but cannot get it back without paying money. I drive round the country to see customers so I have good experience of evaluating them all.
My new car is arriving in a few days days which will have sat nav built in so it's not a big deal.
Why are android equivalents so poor compared to IOS? Check out the trainline.com, Apple version is fantastic(you can download timetables)< Android version is awful!!! I have a top end dual core phone but I have to use Apps that look like they were designed for a spectrum!
This sounds harsh, there are some great utlities on the Android Market, I just get the impression Google really aren't that bothered with it, it looks very amateur and presentation isn't a patch on the app store.
Last point is the back button is very easy to hit when browsing in landscape (Small but irritating problem)
As it stands I will be selling my iPhone 4 and keeping the SG S2

The only thing the iPhone 4 has above it is the App store (please google develop this), I'm not as reliant on the apps any more as I can go directly to the lash enabled website.
I know you can do a lot of this by Jailbreaking the Iphone, I for one cannot be boothered with the constant battle against Apple to keep re jail breaking if you want more features.