As in pdaXrom, I would assume that OpenOffice is a massive waste of time. It runs so incredibly slowly for me on pdaXrom that it would be faster to find another computer and use it.
I would stick with AbiWord/Gnumeric if I were you (but I'm not you, so if you really want to try, go ahead...just know that it will be horrendously slow). In my experience, OpenOffice is slow enough on a desktop PC let alone on an embedded device (It runs sufficiently well on my dual core AMD 4400+ processor with 2 Gb of RAM, but on my older computers it takes copious amounts of time starting up).