Also remember that at full power, your recycle times go up and you will drain the batteries on your flash faster, so carry spares. I suppose it comes down to what kind of shots you want - do you want to light the entire room or focus the lighting on your subject and de-emphasize the rest of the room? With bounce, you have little control over the ratio of light falling on the subject versus the background and little control over the direction of the light if you are bouncing from the ceiling.
The original issue in the thread was the problem with color balance from competing light sources. In Curtis N's thread, he had virtually no competing light sources in the setting where he shot the two stage producers, so his flash, colored by the ceiling upon which he bounced his flash, dictated the relatively uniform color. His exercise was to demonstrate that a 580EXII could be used to bounce off of a high ceiling, not that it would eliminate the issue of multiple color temperature light sources. The flash only had to illuminate the relatively unlit scene, so pushing the ISO gave him the "correct" exposure for his scene. In a setting like the banquet room above, remember that when you shoot full power and increase your ISO, you are going to increase the ambient contribution as well (the pesky tungsten lamps that caused the problem in the first place). So your flash somehow needs to be able to overpower all of the lights in the scene (including the background) if you are going to get a uniform white balance from bouncing our flash only. In this case, you probably want to go to the venue ahead of time and experiment with the bounce to see if you can balance the ambient and flash contributions in manual mode with a combination of shutter speed and ISO. If you can, try to get your subjects to move closer together and crop in tighter on the faces so that most of the extraneous background (like tungsten lamps on walls) is eliminated. Usually, if you need the background in the shot for context of the location or event, then it will (hopefully) be more interesting and you can light it with bounce so that it, and the subject, gets equal emphasis. Remember that, when photographing people, you want a reasonably good representation of skin, so take some reference shots with a white balance card if you are going to bounce. The more locations and surfaces that you use for bounce, the more reference shots you will need if you want to reproduce skin tines properly. Otherwise people may end up looking too blue.
If you can't, then make life easier and get more control over your lighting by using the various CTO or other appropriate gels. This way your white balance reference will not change unless there is an extremely powerful local ambient light source that is different than the gel you choose. Also, get your flash off of the camera hotshoe to give your lighting a little more directionality, and maybe an 80/20 bounce or mini-softbox. You will have much more control of your light and the extra gear is compact and relatively inexpensive. If you use all of these techniques, your shots will also have more variety.
Good luck,
Kirk
PS -Read this case study to help understand balancing ambient fill and flash:
http://strobist.blogspot.com …olling-daylight-pt-1.html