This is absolute BS. That bug number is greatly exaggerated. As for how critical those bugs are, I'd say they are towards the bottom of the totem pole. As for software testing, what does it matter to you? If you were serious about it, you'd have an MSDN subscription already. If you just want to brag, you're not the type who needs it. Just stick with the final. You probably don't need that either, but you're the type who'll gladly apply a bucketload of patches to his/her computer for no reason, right?