Dual m4 256GB vs. Single m4 512GB

[Prodo123]

This recent $200-for-256GB sale has gotten me thinking.
Which setup would you prefer?

I have a 2011 MBP 15" with SATA-III in the optibay slot.

 

[SDAVE]

I would wait for the 512 to go on sale if you really need 512GB of SSD space. It should be around $500 in a few weeks.

 

[YoYoMa]

I actually just went with the dual m4 today. Curious how much I'll regret it in a few months with all of these decreasing prices. I'd prefer a 512, but as the dual m4 is over 100 cheaper, and it's nice to have dual drives for things like scratch drives, etc, I'm not regretting it too much. I'll certainly change my tune when 512s hit 400 though.