Like others here, I've been asked to share my thoughts on Pax partway through the recruitment process. I've enjoyed interacting with guild members through my application thread; the questions range from thoughtful to extremely silly, but have led to some fun exchanges and given me a bit of a feel for the people behind the handles.
In-game (all Republic so far), I honestly haven't interacted all that much with too many guild members yet, but I think that's largely because (a) I've been focused on solo stuff (getting to 55, etc.) and (b) I haven't been on TeamSpeak yet, which is apparently where much of the action happens. I will say that one particular guild member has been extremely friendly and helpful - running me through Oricon to help get my new 55 geared up, checking in to see if I need any help or want to start running FPs, etc. Everyone in the guild seems to be very friendly; I just haven't been taking advantage of that yet. I do see several folks from the guild on almost constantly, no matter what weird times or days I log in, which is always nice.
All in all, I'm quite impressed with their organization and friendliness so far; more updates as they happen!