LXDE is fine, but we already know the Pyra can cope with XFCE, so we don't particularly need to lose features by moving to a more primitive DE as standard (you're free to install LXDE/Englightenment/CDE etc. if you'd prefer them of course). I suppose you could argue that since the Pyra can run full power desktop DEs like KDE/Gnome3, but I at least prefer something more traditionally WIMP. I've been using XFCE 4.12 on my Arch notebook since the updated packages were released. The new auto-hiding panels and per-workspace backdrops are nice features I've already made use of.