Thanks.
I found some configuration issues, and I corrected them. The main issue is, that the results that are showing up for “xbox 360 controller” are still different from what you would expect, because they are more relevant. Each has more keyword matches in the title, as well as in the content and in the taxonomy terms as well.
The only way I could achieve the expected behavior is by completely turning off the indexing in the titles. It seems to give more “expected” results, because a lot if items have repetitive keywords, which make them more relevant.
It is far from perfect, but you should likely get more expected results now with a much better performance as well.