If the Parallela came with at least 2 GB of memory, then I'd be confident that it could comfortably run Ubuntu or any Ubuntu-based distro.  Keep in mind that any new Dell desktop computer you can buy today comes with at least 2 GB of memory, and any new Dell laptop computer you can buy today comes with at least 4 GB of memory.  Furthermore, you can upgrade the memory on Dell desktop and laptop computers.  (And I'm sure that most people buying new desktop and laptop computers today get considerably more than 2-4 GB of memory.)

I've tried Ubuntu-based Linux Mint (with LXDE) and Xubuntu with 2 GB of memory in VirtualBox (around late 2011), and they felt slower than Linux Mint Debian Edition with GNOME2 and 512 MB (in VirtualBox on the same computer) did at the time.  Thus, I'm skeptical of the speed of Ubuntu with just 1 GB of memory.  Keep in mind that most brand new PCs with 1 GB of memory had Windows XP pre-installed, and Ubuntu and its derivatives were considerably lighter in those days.

While the Raspberry Pi has just 256-512 MB of memory, that is plenty given that its official OS is Debian.  With no GUI or a very lightweight GUI, Debian runs well even on 10-year-old computers lacking resale value.

Thus, Parallela should come with more memory to support a Ubuntu base or should come with a lighter distro.  If I buy one, it won't be until there is great support for Debian or a distro based directly on Debian.

While there are alternatives to the official setup, there's usually less support for these unofficial setups.  In my experience from trying Linux distros, the edition with the official DE is the smoothest, most polished, and best-supported one.  I currently have Snowlinux 4 Glacier with MATE installed on my main desktop computer, and it's MUCH better than the Xfce version (which I also tried).  That's no surprise, as GNOME has always been the main DE for Snowlinux.  The developers have more experience with GNOME2/MATE than with Xfce, and most of the users use MATE, so the MATE edition gets more support and attention than the Xfce edition.  And the Linux Mint Debian Edition no longer offers the Xfce version, as few people were using it, and supporting the MATE and Cinnamon versions was a higher priority.

-- 
Jason Hsu <jhsu802701 at jasonhsu.com>