When someone posts a comment such as "I haven't tried software XYZ, but it looks like it might meet you requirements", we keep it (unless it's spam). Why? Because it is helpful and is better than nothing (or could even be a better solution than some of the actual answers posted).
But when someone posts an answer like "Try software XYZ, it will work well.", we typically delete the answer, because it's not a high quality answer (it doesn't contain sufficient information).
The result, in the second case, is that we lose a recommendation that would have otherwise been kept if it was originally posted as a comment.
What do you recommend we handle the dichotomy between these two cases?