What do you like best?
Their support... plain and simple. They will almost do all of the work of setting up your webinar, as long as you give them the video and answer some questions. And they do it in about one business day.
Also, they have a very convincing interface that feels like a true live webinar -- with chat, and all.
What do you dislike?
It's ugly. For most people, that doesn't really matter... but occasionally I want a more appealing "Web 2.0-feeling" UX. Stealth seminar is the workhorse... not the show pony.
Recommendations to others considering the product
If you want to switch to automated webinars, you want the best support in the industry, and you don't need the sexiest of UX, then Stealth is 100% for you. If you don't care about support but you want something that looks slick, then consider other options.
What business problems are you solving with the product? What benefits have you realized?
Lead generation through webinars. I have generated tens-of-millions of dollars with automated webinars for myself and my clients, and Stealth has been my go-to platform in 80% of those cases. Stealth allows me to be live with an automated webinar in about 1-2 biz days, fully integrated with my other tech stack, etc.