Agree with most of the PPs re the waiting around, esp for formal photos, places to sit, being starving, etc.
Fix that and you're onto a winner.
If the B+G are happy, and obviously in love and delighted to be doing that, in front of people they love and who love them, then most of the guests will be happy and delighted for them too.
I LOVE a canapé, but if that's all you've got to keep you going between (say) 11 and 4 then there just won't be enough, because for the guests then that's "lunch", so if you're doing canapés, you need to appreciate one mushroom vol-au-vent wafted around every 45 minutes whilst there are 3 hours of formal photos - that isn't going to cut it!
Personalising things for your guests is lovely. We got wedding favours at one (I'm sure none of them cost more than a couple of quid) but the B+G tailored it to personal things - sweets they knew we liked, etc, and each "box" had a photo of us on the lid (photo-shopped to make it wedding-y). That was really sweet.
Speeches which are short/funny/sweet or which mention the guests. I once attended a wedding on my birthday. The bride knew it was my birthday. Never acknowledged. It was a shit birthday for me... had to arrange childcare for my DD, no time for any presents or cards. Nothing in the day anything about me (obviously). But it was my frigging birthday. the MoH had given birth 2 days previously, and her daughter was toasted. This probably sounds mean, but I felt I was generous to give up my birthday for my friend, and it wasn't acknowledged. And you can't make a fuss, cos it's their wedding.