This may be a good bit behind your time table of deciding whether to use AC or not. I've been working on changing our cart over, which was basically a buy now button set up to a full fledged cart. I've tinkered with many of the others out there but decided on AC because of the remote carting feature, full custom url's, rewrites and such. And I was able to take my existing html based pages and put them in categories that so far are working fine.
Every single cart service, and I'm only interested in hosted plans, not some free software to download because to me, many things can go wrong and I don't need the hassle or down time due to my own inability to manage such things...but anyway, every cart has it's nuances, hang ups, and "makes no sense" kind of things when you're learning to use them.
AC in many ways was not intuitive to work with for me. Other carts seemed easier on some things...like toggling a button to ship a product for free for instance, but once you go through the processes of setting up an AC cart, it get's much easier to work with, and begins to make more sense. Product variations are one example that comes to mind.
All in all, I think because of the flexibility and capabilities within the AC system, it's worth looking into. For me the template system was really easy to work with and the multi store feature helped get several sites online fast. There's really always room for improvement I guess you could say, but so far, despite a few glitches and oddities which eventually were worked out, I'm happy so far with AC. I've worked tech support over pretty good and for the most part they've been helpful and timely in responses. And as I work with AC more I'm getting more comfortable with it and how it works.
Here's wishing you the best with your cart research...it's quite an undertaking to find something you're really comfortable with in the end.