ok.

i have been restarting my computer all day testing different configurations and looking at many, many...many post-gdm bootcharts...  in fact i triggered 2 'force checks' on my laptop so i rebooted at least 60 times haha

anyway, i have a few interesting things to report.  i am running Gutsy final with all updates as of 10 minutes ago.

before i say anything about compiz/etc., i wanted to ask/point out a few things.  

first, while looking into this problem i noticed others having their gui desktop completely freeze after enabling/disabling certain startup apps and then attempting to press the logout button; additionally, some experienced this after mysterious errors earlier in the day but did not notice a problem until they tried to log out.  i encountered this very thing when attempting to barebone my session down to essentials and pinpoint this 'slow' boot reason.  i disabled all plugins to compiz using CCSM, except 'dbus' and 'workarounds'--additionally i disabled ALL startup options in Preferences>Sessions (i will brief upon another possible bug regarding this in a moment).  under this config i still got a brief moment (always>2sec) of gnome-panels before everything goes black for 15-20 seconds.  HOWEVER, when i tried to reboot using the logout button, my computer locked up.  the source of the problem was due to 'Power Manager' being disabled in Preferences>Sessions.  my guess is the logout button is trying to query said program to try and determine if 'hibernate' or 'suspend' should be an available option on the logout screen.  this bug is reproducible simply by disabling 'Power Manager' under Preferences>Sessions, rebooting, and attempting to log out using the gui button.

second, even though i had disabled ALL startup apps except 'Power Manager' , bootcharts would sometimes show these apps initiating.  this may have been because i hard reset my laptop the time before because of the logout bug i described above.  also i could not figure out how to disable the deskbar applet at all, but i am confident this has nothing to do with our issues.

third, not related but someone might want to file a bug rep. in the appropriate place, nm-applet will occasionally place the 'Wireless key needed' dialog on the desktop of another user logged in, instead of the current user.  i was logged in as a regular/desktop user and the dialog appeared on the poweruser that was logged in.  i had to switch users to enter the WEP key.

fourth, i noticed this EVERY time in compiz and only once with metacity; xsession will try and initialize gnome-volume-manager and gnome-power-manager only to by terminated within less than a second and reinitialized by either init or getty.  bootchart:
http://sweetsinsemilla.googlepages.com/compizdbus-workarounds-pwrMAN-slow_a.png
which leads to my final ?'ion.....

fifth, why do some bootcharts show init starting many gnome-* apps, and other show getty?  i viewed subsequent charts and there appeared to be no reason for the swapping...not sure the repercussions of this.  lastly, gnome-settings-daemon and gnome-vfs-daemon will sometimes be initialized by dbus-daemon, other times by getty, and still others by init...  does this even matter?  this behaving was very sporadic in compiz but very consistent with metacity. some bootcharts:
metacity:
http://sweetsinsemilla.googlepages.com/metacity-pwrMAN-quick_and_nofreeze.png
http://sweetsinsemilla.googlepages.com/metacity-noapps-quick_but_freeze.png
http://sweetsinsemilla.googlepages.com/gutsy-20071115-2.png
compiz:
http://sweetsinsemilla.googlepages.com/compizdefault_plugins-pwrMAN-slow_an.png
http://sweetsinsemilla.googlepages.com/gutsy-20071115-7.png
(see bootchart @ #4)

IN SHORT(kinda): i discovered many others to be having problems with the ubuntu package of compiz.  i think the wrapper script 'compiz' is sending the wrong params to 'compiz.real'.  i had no problems whatsoever when using metacity, with the exception of the logout bug, but that is independent of the window manager.  all bootcharts showed the same boot times for both metacity and compiz (compiz a few sec longer for obvious reasons).  basically, all my apps were loading and my desktop was "there", i just couldnt see it until something 'snapped' it back, about the time it was completely loaded.  the reason the gnome-panels showed for a brief period was because the window manager (compiz.real) had not yet been started.  notice on that bootchart above, compiz.real starts less than 2 seconds after gnome-panel.  i think this may be the problem for everyones 'slow startup'.  its not really slow, compiz.real is being mis configured by the wrapper script (compiz) or something along that line, and the gui environment is temporarily killed when compiz.real is actualy initiated.

sorry for the lengthy post; i want to solve this ;)