I have the same setup as you, except a 15 MBP w/4GB. I find OpenOffice and NeoOffice acceptable in terms of speed.
If you do not use the database, then consider Symphony 3, basically OpenOffice from IBM. It seems snappier, more compact, and does a decent job of offering word/spreadsheet/presentation work. Be sure to get the Symphony 3 version, not 1.3 version.