Well I'm not actually laptop bound. I'd say I use my laptop and desktop fairly equally, though I do big projects on my desktop PC with multi-monitors. I'm fairly sure I can fit my OS and apps on the laptop with the 32GB drive and be okay. Desktop, no. The X25-M is 80GB which would work for my desktop, if the -M is fast enough for writes with MLC and RAID 1.
I've never worked with tape backup. I guess tapes are reliable? I don't need a whole tape library, I just need to have one tape that I swap out in a secure place periodically, weekly etc.