There are a lot of variables with that. So here are the pros and cons.
1. Steel tanks buoyancy fluctuates less than aluminum tanks. This provides an opportunity to reduce weight on your belt. That to me is a big bonus
2. Although steel tanks typically have lower fill pressures, they can in many cases out perform the standard 80 cube aluminum’s. The HP 108+ is a favorite of mine. Even if you are an air hog, you will typical beat out anyone on your boat. Even if they have a 100 cube aluminum. Note the + as it means you can over fill the tank
3. Steel tanks are more negatively buoyant than aluminum... once again, less weight is needed
4. Steel tanks take a little more care and inspection as they rust.
5. Din valves commonly come on steel. This allows you flexibility if you purchase a yoke adapter. Din I’m my opinion is a better system for many reasons, but the most important is that you know the health of your o ring.
Hope this helps