Is ace a positive word?

I'm curious, could you please clarify for me if 'ace' is indeed a positive word? I've heard it used in various contexts, ranging from praising someone's exceptional skills or achievements to referring to a high-quality or superior item. However, I've also noticed it being used in a more casual or even ironic manner, which sometimes makes me wonder if it always carries a positive connotation. Can you shed some light on this and help me understand when 'ace' is appropriately used to convey positivity?