I work in the winters as a marine biologist, UW videographer, and lecturer for Lindblad Expeditions in the Gulf of California (Cortez is a bad word in Mexico) as well as Belize and Honduras.
Diving there is different from the Caribbean or the kelp forests of my own home. One must learn to take a region for what it is. Personally, I find "differences" interesting. Since there are not reef-building corals throughout most of the Gulf or macroalgae, I spent my first week of diving trying to understand the nature of the food webs there.
Since water temperature and species composition changes seasonally in the Gulf, you will find differences between winter and summer. As a temperate water diver, I found the "warm" winter waters (3mm shortie) welcome compared to the lower 50's of Catalina at that time.
Loreto may be better than La Paz since boat trips to the islands are shorter. However, much of my diving was in the islands between those two towns. I enjoyed Cabo since most species there were more tolerant of human presence and I got good video of normally reclusive ones.
As mentioned, Los Islotes is an interesting dive... both for the sea lions and the diversity of invertebrates (I saw more species of starfish there than any other site I dove). Each site was inttriguing with site-specific differences I found interesting to reflect on.
Approach any new dive environment with an open mind. Don't try to compare it with the others you have dived. Look for what is unique and different in each, try to reflect on how the ecosystem works. I think you can find any new location interesting if you take that view.
Dr. Bill