This is definitely a question where one answer will not cover all scenarios. I'll say that I've never had a couple regret seeing each other though, and I personally like it most of the time because I feel it usually provides more time to accomplish the goal of great images. I'll never strong-arm a client into any schedule they don't like though. I'm not that strongly for or against it and a successful shoot can usually be done either way.

There are a few instances though that may prevent that from being the optimum schedule. Those may include:

• Knowledge that everyone will definitely not be present thereby requiring a split-session anyway (some formals before the ceremony and some after).
• Being restricted by the location's reserved block of time and/or the ceremony time placement within that block of time which may not provide enough time to properly accomplish all the formals prior to the ceremony..

Some reasons for it may include:

• If often provides more time to photograph the bride & groom than is possible after the ceremony.
• It actually calms the bride & groom and allows them to enjoy the ceremony more. No, it doesn't ruin the excitement.
• In the cases of winter weddings, it often allows you to work outside before it gets dark.