ontopic: The certs are crucial for a company - they net you partner points and qualify you to a big discount on the msdn subscriptions.
That was the only reason I did the certifications and the only time I've ever used them. Besides those points they are rather useless - I've never used them, no one ever asked about them (I just looked them on the partner website, I didn't even remember what topics I did)
From the learning perspective I had mixed feelings - as some of the questions were weird/useless, as they required a knowledge of a specific api, in a sense where the wrong answer would have been caught by the compiler, you'd normally use intellisense or hit F1.
So if you're in it for the learning experience, I'd recommend staying away from the learning material and the tests. If you fancy .net/c# pick up Jeffrey Richters excellent book clr via c# or channel9 screencasts or opensource projects or... well anything but the certification stuff.
If you need to use computerized tests to gauge development skills I'd pose a problem, and let them solve it. Compile it on back end and run it against some inputs like pex for fun or http://codility.com/
I mean, c'mon they're ms!
oh, btw: The tests are done in a testing center and are multiple choice.