We moved to sendgrid around the same time. Our deliverability took a hit, and I'm not the keenest on their very narrow window of email data they keep... but no real shenanigans, very straight forward, and the one significant outage of theirs I can remember they handled it well.
SendGrid used to have a free plan but things have changed since being acquired. I moved to SendGrid anyways though and use their free 25,000 emails / month on Azure even though our app is hosted elsewhere:
Funny - I was looking at SendGrid on Twitter and looks like they've had some issues themselves over the last few weeks: https://twitter.com/sendgrid_ops Did you notice anything, or were these very small outages? For all that, they've obviously been a good deal more communicative than Mandrill when they have had issues.
Their API has been very reliable for us. They do have mail delivery delays somewhat frequently (see [1]), but we rarely notice them. They are extremely communicative on their status page, at least.
And twilio seems to be very serious about uptime. Not sure if it translated to all the facets of their business, but phone services being down will lose you customers quickly.
