I will be taking some shots today at an indoor 60th birthday party.
I'm torn between my own beloved 18-200 which I'm quite familiar with, or the cheap 18-55 that came on my daughter's 1100D for it's slightly larger (max f/3.5 versus my 's f/4.5).
The larger ap might help with the low indoors, but then I'll be using the 430ExII as bounced , and the zoom on the 18-200 might help get more candid shots as I won't be quite so in their face to get the shot. But that would put them outside the effective range of the flash to a degree too, so again a larger ap would be good.
I'm thinking I'll carry both , and work from the 18-200 primarily but keep an eye on the images coming out of it and see if I need to change.
Hell, I could even carry my daughter's camera as a "backup" because I've actually been asked to do the photos for the day, so carrying two cameras wouldn't look quite as odd as it might if I was just another guest. Though I am primarily there as a guest. It's a surprise party for a very good friend.
I really do need to get myself some faster glass. It turns out most of the photography I do for others is indoors. My own glass is more related to landscape and outdoor stuff.