I chose the e71 as a cheap but high quality alternative to my work blackberry curve.
I wanted:
Querty keyboard, even for my big hands
Fast internet, 3g & wirelss network access
Emails on the move with attachments + multi email support
Phone can be used as modem/dongle 4 pc
Adobe pdf & word reader
skype, msn messenger, facebook access (free on 3)
slim phone as i have 2 carry my work blackberry curve as well & i wear tailored suits so i dont want a bulky phone
Good gps maps
Dont want to spend £30+ per month on a contract
Good music & video capabilities
Built in + card, memory
Outlook synchability, for backing up calendar & contacts
Good reception & sound
Online share account access
Clear screen
Easily unlockable to other networks
Well supported with add on applications

The E71 does all of this well, all of this is provided built in on 3 + you can add on items. The cheapest sim only deal ive seen is solo+1gb internet on 02, £19 but im still in my 3 contract, £22+£5 1 gb internet. Where reception is bad i just change to wlan so i dont use up my 1gb

It has more features than my blackberry 8230 . i can do 1 handed texts/emails if i want, & the internet is much faster. The phone is much faster at everything than the curve. I toyed with getting a bb bold but its too big & too expensive in comparison. Also ipod touch screen i dont like & couldnt use it as a modem. It doesnt crash like the curve

Its very good value for money