You may still get £450 for it, but I reckon most people would just spend a couple of hours pressing F5 on newly listed to save themselves £100 - that's what I'd do anyway.
As for iPhone/Android, I use an iPhone 4 and Dell Streak regularly and I found the iPhone to be a bit quicker and more stable, but missed the customisability and just generally found android easier to use. My SGSII is faster than the iPhone 4 anyway, so if you were going from an iPhone to an SGSII, I really don't think you'd miss anything.
Well like I said in my opening post I ordered a HTC HD2 (windows mobile) when it first came out and it was just horrible. Yes the screen was a lot better than the Iphone but everything was just so much hard work. None of the apps like Facebook were complete, every time I wanted to do something it was far too long winded compared to the Iphone and that was when I just sold it and bought a second hand Iphone 3GS for the same amount of money.
That REALLY put me off anything other than Iphones. However, I absolutely refuse to pay infalted 24 month contract rate to get an Iphone. Even just seeing the carphone warehouse brochure that I picked up at the weekend with a seperate Iphone tariffs page make me angry

My 3GS is looking totally battered now so I do need a new phone but the Iphone 4 offers nothing worth upgrading my current 3gs for.
One thing I did hate on the HTC was how unresponsive it was and how I was having to try new firmware from modding forums etc etc. I just want my phone to work. I think thats where the Iphone does it for me with its usability. Everything just..Works.
What apps do you use regularly?
Things that I regularly do on my Iphone at the moment are...
Email (Gmail)
Facebook
Shareprice
BBC News
Sky Sports News
Around Me
Maps
Shazam
Hotukdeals (ihotdeals)
Twitter
Tom Tom
Text a hell of a lot so I need a decent keypad. The Iphone is the best I've ever used and this would be a big selling point.
Only gripe I have with the Iphone is that I have to go and find everything that I want. I'd like to have things like the latest news on my homepage, a few share prices, read a text message while TomTom is running.
I don't listen to music and haven't used mine as an Ipod once so that doesn't bother me.
The battery on my Iphone is annoying too, I do use my phone a lot, doing all of the above most days (apart from Tom Tom) and most of the time my phones is dead by 10-11pm.
I've had a look on my dad HTC Desire which I don't think he has updated in quite a while and it was a little confusing having just a few minutes messing around.
EDIT : I'm far from a Fan boy of apple. I think the Iphones are excellent, everything is so user friendly. I want an app and its downloaded and ready to used in an instant. The facebook app is better than using a computer. Everything just seems so polished to me. If me and my parents are out somewhere and we need to find something on the internet or search for something, it takes me half the time to do on my Iphone compared to my dad htc. I don't know how much that is down to the user though. Guess I'm just a little confused as to what I should do. I fancy a change purely because I'm not paying £35 for 24 months for an Iphone compared to getting a phone like the SGSII for 2/3 of the price.
One thing I must add, my dad has a Samsung Galaxy tab and that has slowed down something rotten, the keyboard is far too unresponsive, takes ages for apps to kick in. If I click on the search bar, i've typed half of the word in befor it even registers on the screen. Thats one thing thats worrying me about making the switch to a Samsung phone which must be fairly similar?