How good are Nik plugins for LR4?

I just bought LR4 student edition, after using LR3 for the past year. (I purchased LR3 during the free upgrade promotion but never got around to upgrading it for free. Stupid and lazy me)

Now, I am considering purchasing the Nik Complete Collection for the academic discount price of $150, I think its still a lot of money for what are essentially presets. I was wondering how good it really is, and if it is worth the money.

How popular is this product? The Color Efex, Dfine, and Sharpener Pro look useful but the Silver Efex looks like something I can do in Lightroom by myself.  How good are they at what they do?