I have an Asus Bamboo laptop that I carry to my 9-5 IT job everyday and also carry with my on any side consulting I do. I have been wanting to upgrade to an SSD for a while but have tons of ISOs, programs, and other things downloaded on the 640GB drive in the laptop now. I use the stuff on the drive so often that sticking it in an external enclosure and carrying it with me isn't ideal. So I bought one of these HD caddys that replace the optical drive: I'm planning on getting a 120/128GB SSD (probably a Samsung 840) for around $100 and putting my 640GB drive in the caddy. Is there any downsides I'm not thinking of? Will battery life be affected badly? I know SSD's use less power than a mechanical drive but since I'm not replacing my old drive will I see a major drop in battery life?