Quality support, Great performance and Amazing up time record.
Incredible deliverability and customer support!
We just completed a comparison of Mandrill and SendGrid here: indiemark.com/...
Ive used Send Grid for mingletrips.com. Works great. We are going to use Amazon SES since we are hosting the next app on EC2. Will give my feedback on SES.
SendGrid's API's make it so easy to integrate!