Autos are smaller due to their limited veg time.
You can grow as many different auto strains in one grow, no problems.
Photos are better for beginners as they can be controlled better, that is, when to flower them.............only once you are satisfied with their size.
Autos use a lot more electricity and are better suited for experienced growers with top shelf equipment.
Photos have decades of development and are generally more potent and definitely, more stable genetically.
I have been growing for 40 odd years now and tried autos for 3-4 years and will never grow them again.
For me, autos have absolutely nothing to offer over what can already be achieved with photoperiod plants.