I'll just say this - I am using Lync client and the company has moved to Lync 2010 backend... it is, I kid you not, a VERY good upgrade. If your IT department has no plans to upgrade they are missing out.
1. Meeting conferencing in app is much improved - no more need for LiveMeeting
2. Presence updates are much improved
3. More social functionality
4. Better Filtering
5. Better VoIP integration
It is quite a bit better as a product. Plus, you can do one click dialing from all links in IE - you see a phone number the new add in recognizes the number and you just click an icon... it's all pretty nice
Me personally I don't want any UI that looks like OCS - Lync is way better.
Samsung Focus (Unlocked) - Mango (7661)
Dell Venue Pro (Unlocked) - Mango - 34GB
HTC HD7 - Mango (7661)