I went down in October, but didn't bring any gear with me after hearing the the conditions weren't worth it.
When I got down there, I ended up buying a cheap pair of swim goggles. Even from the town end of sandy beach, I saw a ton of small tropical fish (mostly sargeant majors, but also a small stingray and several flatfish) around every bit of structure (rocks and what-not). It seemed as though the bottom substrate under the sand is volcanic, so I wouldn't be suprised to find there are lots of unexpected holes and boulders dotting the otherwise sandy bottom. I'm used to 15' vis in the ocean at home, and found it to be slightly better in Puerto Penasco. Still, I was on a 5-day tequilla bender, so I opted not to investigate further.
If I go again, I'll be diving while I'm there.