Hello, I have a Mid 2015 rMBP on which I will run bunch of VM's but I have not much space to hold the VM's. I am looking for a 256GB external disk which should be somewhat portable. I checked Sandisk extreme pro 256GB USB 3.0, did anyone had such an experience? Is sandisk extreme pro capable of running 2-3 vm's at the same time with good enough speed? Of course I am open for suggestions about other devices. Regards.