How does an AT&T variant Priv differ from an unlocked one?

I have the opportunity to buy an AT&T variant Priv for $250 from someone that was gifted this at Good Morning America. I currently have an unlocked Passport (satisfied user but curious about the Priv and on a corporate AT&T plan through my work. Can I simply switch out my sim card and be up and running or does it get complicated by having to work through AT&T somehow and what are other differences between an unlocked version that I should be aware of? Sorry for the long question but would appreciate Crackberry experts input.

Yes you can simply switch sim cards. As for your data, I don't suggest the content transfer app, I've heard nothing but issues with it.
With the ATT Priv, obviously will only work with ATT, and it will have all the att bloatware that in most cases can't be deleted just disabled.