It largely depends on the company -
If I am working for a company where I know everyone will be using Outlook with corporate email, I will generally put reports straight into the email, because I know the formatting will hold up. It means that people can then search etc. It is just convenient.
If I am working for a company where everyone is a contractor, I send the report as a PDF and any key action points in the body.
This is not just rehearsal reports, this is any reporting - even when I had to do profitability or P&L reporting - I give the summary in the body so that those that don't really care about the nitty gritty can go "Okay, cool, we are $1.50 above budget!" or "Oh... we are a bit behind, maybe I will stop stealing boxes of gaffa tape and taking them home this month"