Considering a Diamond

Heya guys! I'm new and from the UK

I was considering a Diamond and was looking around the web for information and everything i have found so far seem so polarised in opinion and out of date (with regard to firmware). I had a play with it in store today and it did feel a little slow.

Anyway i would be picking up a diamond On Orange UK (Been offered 300mins unlimited texts and Data for £20 which i think isn't a bad deal)

Ive read a lot about the Diamond being kinda sluggish and problems with the underlying winmobile OS.
and as i have no experience or idea about the mods i've seen here or how to make sure if i made any changes i could get it back to keep my warantee.

anyway my questions:

1) is there any justification to the sluggishness comments ive seen?
2) i know orange firmware will come bloated and looks ugly as hell  how easy would it be to change the firmware?
(it seems to be most things ive seen are related to US carriers)
3) is it easy to back up the current firmware and reinstall incase i have problems and need to return it
4) does it have true GPS? (works without a data connection)
5) how easy is the keyboard to use/get used to

6) Diamond Vs Touch Pro? apart from the obvious size and weight are there any advantages to go diamond?

cheers guys, and im real sorry if this is in the wrong place!    

thanks for the help folks. i'll be on my way.

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