I have pentagram cerberus wifi AP and it is throttled to minimum (about 10mW). Normally netwalker gets 100% signal through 2-3 thick stone walls (walls - 40cm total distance - about 7meters).
Problem with keyboard absence is obvious. I will probably never buy a tablet (standard oldfashioned styllistic, compaq t1000 or modern one ipad, galaxy tab) because of lack of keyboard.
I can agree with slowness of netwalker ubuntu.
But in this field is a bit to tweak.
-close all unneded gizmos (system monitors, sendmails, httpds, ftpds, smbd)
-get rid of pulseaudio.
-remove most of panel plugins
-create a bit of swap, not much 256-512meg is enough. This will allow to move unused stuff (mostly used only during startup and shutdown
)to card and leave more place for buffers.
-do not open too much tabs in firefox.
-close unneeded applications
-get iqnotes and tomboy notes
-change default terminal to something lighter.
-use mpd and ncmpc for playing music.
-install some lightweight browsers (midori, epiphany or other) and use them.
-use xbindkeys (see my post about zaurus configuration for that), or built in gnome -something to command your device by single keys.
I am not suggesting change of default WM. Others have a lot smaller usability for "palmish" device. And tho make them as functional as default is quite workeater.