Seems to me it is time to try and summarise ... and suffer the consequences.
Ain't one solution for everyone ...
& power consumption
not an issue / want high end performance and/or big screen
, then go big PC, go new. (And argue about merits of Mac vs. Toughbooks etc forever)
an issue, power not, only want basic performance with big screen, or want redundancy on the cheap
, then go big, go old. (And look condescendingly or enviously at the above group)
 Price and power consumption
an issue, happy with smaller screen and modest performance, and want redundancy on the cheap
, then go new, go netbook. (Go crazy if you always have to work on that 10" screen.)
Best piece of universal advice was to get backup sorted. We all need it.
Find a relatively dry space, a Toughbook, or make the PC area a raincoat.
If all you want is to run OpenCPN
, etc, you may not need #1. (What you might want is a different question!) I generally use #1 in dock
, and #3 for nav and travelling off the boat. Mix and match.
Horses for courses ...