Should I use Sendgrid for email delivery?

Yes, I tend to recommend it pretty strongly, for a few reasons.

1. It tends to improve deliverability, especially compared to sending email directly from your web server.
2. It helps you to understand if customers are not happy with emails. This is an important one. If a customer clicks the Spam button in their email client, Sendgrid tracks this, so that we can know which emails to disable or fine tune.
3. It gives you analytics on what types of email clients your customers are using. If you run into a weird problem that only affects Outlook 2007, you can have an idea of how many people that's actually affecting.
4. It gives you other fun analytics that may be useful as well.