Mac mini performance with Thunderbolt display

I am curious to know how well the Mac mini will perform with the new thunderbolt display for everyday use.

The system I will be looking to purchase is:

- 2.7ghz i7

- 8GB RAM

- Amd Radeon HD 6630 with 256mb GDDR5 memory.

- 750gb 7200 rpm drive

I will be linking it up to the 27" Thunderbolt display. However I am wondering how well the graphics card will handle the large high res display. Will it be sluggish when I have lots of apps and windows open?

I was in the Apple store and had a quick play around on the standard 2.5ghz i5 model (4gb ram, 5400rpm HDD, AMD 6630 GPU) and when I had 8 safari windows open and entered expose the animation took a second to occur and even then it was sluggish and the animation was jaggy and not smooth at all.

Yes I know at the amount I'm spending I could get an iMac, but I've had so many issues with them ranging from buzzing power supplies, yellow screens and even had one die after a software update. I've been through 13 iMacs and every single one had issues so I've given up on those.

Thanks