I use both in different applications. Overall SES is no-frills but does exactly what it says it will. Deliverability is on par with SendGrid assuming your traffic is legitimate and not spammy.
The main difference is that SES lacks significant tooling. You need to roll your own monitoring, logging and block list maintenance, all of which can be a surprise coming from tools like SendGrid. Once you do all the work though, it’s largely set it and forget it.
