Dave
http://www.degrootphotography.com.au/
Canon EOS 1D MkIV | Canon EOS 5D MkII | Canon EOS 30D | Canon EF 400mm f/5.6L USM | Canon EF 70-200mm f/2.8L IS USM | Canon EF 17-40mm f/4L USM | Canon EF 85mm f/1.2L II USM | Canon EF 35mm f/1.4L USM | Canon TS-E 17mm f/4L & some non-L lenses.
yeah that might work for u but not good enough for me, posed shots right after ceremony might last about 30 mins max, and I didnt see the use of it for that either since I dont shoot groups at f1.2 its a waste, other lenses like my 70-200 L, or 24-70 for example will do the job better. But it is exceptional for creative shots or for couple/individual shots on location - when time is not of the essence.
I had a quick test of the new Sigma 85 f1.4 yesterday, and hands down I am willing to say it is a lot better than the Canon 85 L, much faster and accurate focusing and lock, lighter and smaller which is great, and no diff in IQ. I dare say this will be a weapon for wedding photographers soon once ppl see the benefits it has over the Canon 85 L - and inspires more confidence in shooters in dark and low light environments. I will possibly buy one next month when I am in HK for shoots.
Focus isn't so slow that you can't use it in those circumstances. Post wedding shots for me are usually 30mins to 1hr depending on the couple.
I have noticed that the focus speed and accuracy is greatly improved on a 1 series body. The 5D struggles on the outer focus points so a different technique is required.