Well with wp/wc I can have a shop up and running in just an hour or so. There seems to be a plugin for darn near anything you can imagine and most are free. I do love the auto update of the backbone and all plugins. I guess the page editor is growing on me, but it used to be quite confusing. I like the media area and "drop in" ability of things like youtube videos. Certain things though like page and product meta tags I still really don't understand which is a big problem. The database structure is totally different from zc. As i understand it, everything is some sort of post. Whether it's a post, a page, a customer or a sale. I might be a little off there, but it's confusing to me. Programming anything in wp is a nightmare for me. It's all hooks and I honestly have no real idea how to work in that system. Then there's the menus and widgets which seem to be interconnected somehow. I can never figure out where I need to go to make changes to different menus or links I have on the site. I tend to login as admin, visit the front side and click the pencil next to the item i want to modify.
With zencart of course you know theres a process there. Gathering up all the plugins you want, uploading, making sure you're not overwriting an already edited file n such. That's really no big deal though, just keep notes and pay attention. I wish it was easier to upgrade/update a zc install. I'm still not great with classes and methods, but it's far easier to figure out than hooks and loops or whatever. I love the developers tool kit for stuff I don't already know. Makes it super easy to track down where you might want to make a change. I really like the database structure too. Over the years I've written a few simple mods of my own and making sense of data and cross referencing records is normally pretty easy for me. The metatags module file makes it pretty easy to change the way tags are built and the metatags languages file makes it super simple to define custom tags for any page whether manufacturer, define or ezpage. And then of course the product metatags from within the admin is really straight forward.
I know I had a lot to say here and might not have covered everything, but all in all zencart is my favorite hands down. The community is amazing and help is normally just a post away.