Well first off, that's an expander backplane from my quick google search so you're going to be limited to the single port for ALL drives connected, combined... as-in you won't come near to maxing out SSD performance based on total # of drives in use.
Is a SAS3 HBA > than M1015 ... yes, but again if you're using spinning drives on an expander backplane it's likely not worth it.
If you've got 24x SSD in there you need a non-expander backplane with 6x SAS connections and 3x HBA to get the 'best' you can with 6 ports.