Me, Mike, and Brent just had this exact discussion on Friday night. I dig the tights because they're so comfy, but they are crazy slippery and they make the game extra fast, which completely flies in the face of almost everything I do. I'm a grinder, slow and steady. So the cotton tights work well for that. Gi pants work best for that. In fact, I've been slowly trending back towards gi pants lately.
Mike, a spats aficionado, was saying that you absolutely must have ankle sleeves if you're gonna wear spats. Makes sense.