What do you like best?
This might be the best mockup program I've used so far. My coworkers love it and I've found that it's user-friendly enough to even accommodate me—that being said, I'm not very UI savvy. So take from that what you will.
What do you dislike?
The toolbar can be hard to track down and, along with that, the program overall doesn't offer a lot of guidance. I had my coworkers to help me, but I think if I'd been using it alone, it would've taken me a lot longer to get acclimated. It would also be nice to have more export options, but I'm sure an update will bring those eventually.
Recommendations to others considering the product
It's definitely worth a shot if you're in the business for it—if not, I'm not sure it's a software program you'd necessarily need.
What business problems are you solving with the product? What benefits have you realized?
It definitely saves time and headaches—and that's kind of what most software is for.