Matt Segal has the 24LII - I have the V1. I have dove w/ my lens used in the Aquatica 5D housing. Autofocus is fine - the lens is f1.4 afterall. If you can't get focus, you can always use the * button and lock focus on your hand or fin.
James, when you used the 24L in your aquatica 5d housing did you have it in the 8 inch dome port without and extension rings? If so, I presume there were no problems with the reflected image and the size of the glass on your lens and you were happy with the results? Thanks again for your help.