Saffire Octopre or another Pro 40?????

I am looking to expand from 8 to 16 channels for a live recording project. I am currently using a Focusrite Saffire Pro 40 and am intending to extend it with the Octopre connected through ADAT. However, the price is not much different to buying another Pro 40 and i was wondering if anyone knows of any advantages of doing this.