I am going to take the opportunity to say I personally dislike that Yoda comment a lot!
Here is a completely awesome answer framed as a suggestion...
However, when the person answering actually doesn't seem to know what they are talking about, I usually downvote and comment to say something like "have you tested this?". If the suggestion is bad, then I vote to delete the answer, and if it misses the point of the question I flag it. If I know the suggestion is good, I will upvote (and edit if needed)!
"Use y because x is broken" could be a perfectly fine answer if x is really broken, and "Use y because it's better than x" would be a perfectly fine answer with justification. Or, it could be completely wrong, which would merit a downvote and comment, or, again if it misses the point of the question, an NAA flag.
My point is, neither of the cases you mention would automatically imply a particular course of action in my opinion - you have to decide on a case-by-case basis what to do!
Once you've decided on the right action, and the right action seems to be a downvote, then the fact that you don't feel like losing a point seems like a baaaad reason to use a flag instead. Use flags... when the post deserves a flag.
