I have used both, and I agree with your analysis. The great thing about MailChimp is that it lets you see the email in different clients. That is really the hardest thing about sending emails. However, you can use that service without doing everything else through MailChimp. Also, once you get the hang of it and develop templates, it no longer is much of an issue.
So with these factors in mind, I had been staying put with Aweber because they met a number of these criteria. But I knew that I really wanted to up level my email marketing and put more customized sequences and automation into place so that the user experience could be much better, and I would have a clearer picture of my audience and what they want from me.
The only other thing I would have mentioned under design is to not underestimate the power of colour and textures – in my hunt for a theme that I actually want to work with, I’ve narrowed it down to finding a minimalist theme and just giving it a hint of colour to add some flair. Otherwise things can just detract from your content just like you said.
After you have entered your "List Name" you will need to enter a "List Description." Here is where you will describe the kind of information you'll be sending from this list. There is a 400 character limit for the "List Description." Subscribers will see your "List Description" on the unsubscribe page if they ever go to unsubscribe from your list. Once you are done entering your "List Description" click the "Next Step" button.