I've got an OCZ Vertex 3 SSD (120 gb). It's getting close to full and I was wondering if it's better to upgrade to one of the 512gb (crucial, samsung, etc) SSDs or if it's better to get one of the PCI-Express / SATA-express cards or an M.2 card? I want it to be my primary boot drive and I'd like a notable improvement in speed, if possible. Thanks and looking forward do your advice.