I agree, a small SSD drive in an external box with USB 3 and eSATA connections is quite good for testing new versions (daily builds) in several computers. (I have a 60 GB OCZ-AGILITY3 in an AKASA box). I'm also booting from USB 3 pendrives (Sandisk Extreme), which is quite an improvement compared to regular USB 2 pendrives even in USB 2 ports because the flash hardware is not limiting the speed.
This is a 1.66 gHz Atom dual processor 1 GB netbook $250 with a 1600x900 external monitor $89 and wireless keyboard & mouse $20 running saucy ubuntu O.K. I like lubuntu fine provided I installed Firefox and Libre and Nautilus....easier just to run the fatter ubuntu. I'm not a unity fan - I just tolerate it. BTW, seems to me ubuntu is less sluggish on saucy than it was on pangolin.
BTW, booting saucy off a $80 SSD (fast!) USB case $20 because I don't trust the unstable ubuntu development level - could clobber the main hard drive esp. the boot....I keep windows 7 as well as stable ubuntu's on the hard drive for when I pass the pc on....I've had to do a grub rescue several times over the last few months.
Hmmm. Wonder what Peppermint OS is. I occasionally run Linux Mint because it's more user friendly about proprietary code than ubuntu is.