I think the key things that just plain make the camera work better are the power management settings David talked about above. The camera has a reputation for being slow to start, very slow to wake from sleep, and very slow to write data to the card. So, first, get a good fast card (I read a comparison and the SanDisk Extreme Pro seemed to test the best and its working well for me) and make sure its formatted by the camera. Next, turn off all energy management features, such as an automatic sleep time and the energy saver mode and OVF energy saver mode (I forget what they're called, but easy enough to spot). And turn ON the quick startup mode. Then just leave the camera on while you're shooting and turn it off for breaks of more than a minute or two. When you switch it back on it will start up a LOT faster than if you let it go to sleep and then try to wake it up. The cost for all of this is battery capacity, so carry an extra. Or two.
Everything else is kind of what suits your taste. I'm finding that leaving the ISO on auto most of the time works really well because its sooooo good through the ISO range, at least up to 3200. If you have dynamic range set to 200% or 400%, the auto ISO will play some tricks on you in terms of using insane low iso settings (like 800 in good light sometimes!). I prefer fewer tricks, so I leave dynamic range set to 100%. In really changing light situations, I'll occasionally turn off auto ISO and assign the fn key to ISO, but I'm not finding the need to do this often personally. If they had the ISO menu set up as one menu with AUTO as one option on the menu, I'd switch back and forth between auto and specific manual settings more often, but as is, I'm generally either gonna leave it in auto for a shoot or leave it in manual the whole time.
I'm also using the Velvia film mode most of the time, but in some situations its just a little TOO saturated, so I'll put the film types on the fn button and switch as needed. When Apple comes up with RAW support for this camera, I'll see about shooting raw, which I do with all of my other cameras. But these jpegs are so INSANELY good that I may just leave it in jpeg for the most part and actually use the raw button for the occasional challenging shot. if its set for jpeg and you hit the raw button, it seems to shoot raw+jpeg rather than switching from one to the other. Also, write times are a non-issue with jpeg but a much bigger issue with raw and raw+jpeg - another reason to shoot jpeg more and raw less. And there still seems to be PLENTY of information in the jpegs to do B&W conversions with Silver Efex with plenty of latitude.
The AEL/AFL button settings are pretty standard - on/off toggle or hold for on and then what does it lock - exposure or AF or both...
Yesterday I was out shooting in bright light and wanted to go for some motion blur but at 1/15 shutter speed, there was too much light even at iso 200 and f16, so I used the ND filter a fair amount. So for that session I set the FN button to turn the ND filter on and off.
So, there are at least 3 things I'm using the FN button for - the camera could really use another user-configurable button or two, which should be fixable in a FW update. Please, please, please!
I'm shooting with the OVF 90+ percent of the time, but I do occasionally use the little lever in front to switch to the evf in low light (it gains up pretty well) and for subjects in the 3-4 foot or closer range to assure that the focus area is focussing on the spot it says it is (the OVF is a problem at near distances in this regard). I sometimes have the gridlines and level turned on and sometimes don't I'm using 1.5 second auto-review and leave my eye up to the OVF - which is the neatest trick I've ever seen when it automatically switches back and forth. That quick second is enough to see if you really screwed something up badly. I'm using the LCD screen almost never except to review a bunch of shots.
But really, all of this stuff is user preference EXCEPT the energy saver stuff which slows the camera down to an unacceptable degree. So, when you get your camera, set those things asap and you'll be happy enough to play around to see what else you like and don't like.
I hope you all get your cams soon so you can get past the little niggles and start having fun. Because after a day or three or getting used to the camera, its a pure joy to shoot with.
-Ray