MobilePro 880 - v. 4.0_RC5 ?

I just installed 3.1.1 via FTP on my MobilePro 880 last night.  Very smooth.
No issues so far (just need to kill IPv6).  No kernel messages popping up
like I had on my 780 when I last looked at NetBSD/hpcmips a few years ago.

Before I get too far into this... is there a compelling reason to install
4.0_RC5?
I see there've been some WPA updates which might be helpful.

Also... any recommendations wrt X window managers and or some useful
lightweight X apps that work "well" on the 880 would be appreciated.

I'm not expecting much.... screen (either console or in rxvt), w3m (a simple
browser with some graphics would be cool too), native X editor for meeting
notes, ssh, epic (or similar console irc client),  running X apps or VNC
from another machine on the net.