Yes, but you've read Sendy is connected to SES right? So you're still getting the benefits of solid deliverability. Or are you saying SES deliverability is not as good as Mailchimp et. al?
SES is as good as Mailchimp and very inexpensive. Too bad Mailchimp phased out Mandrill, which was reasonably priced and had a nice interface. SES has no interface at all but works great.
If you like SES you should check out Email Octopus. It hooks up to SES and gives you a nice GUI for putting the messages together. We moved a good sized client over to them and their marketing people wanted a GUI and it filled the niche nicely.