The Dell Venue Pro is finally joining it's brethren to receive Windows Phone 7.5 Mango. This means that Windows Phone 7.5 has now been deployed to all the Windows Phone devices and should be available to all users.
The Dell Venue Pro has it's own unique design with it's portrait QWERTY keyboard, but shares it's internal specs with the other Windows Phones.
Microsoft has been strict with the hardware specifications of their devices and also ensured that the Windows Phone UI cannot be customized. This of course results in quick updates, so you can't really complain too much