As it's cloud based, I can begin working on my presentation at work, share it with my colleagues so that they can review it, open it on my smartphone in my way home to review it, and finish it at home.
The sharing part is the best part: you don't have to send your first draft then receive it back, then modify it again and send it back so at the end you have 10 versions of the same presentation. Now, by sharing the presentation, everybody is working on only one document and so there is only one version of it. And do not fear if there are errors, you still have a "time machine" to go back to previous versions.
As always with cloud based apps, no internet means no access. Except this point which is not a problem of the app per se but an inherent problem for all cloud based app, the only problem would be is sometimes lack of compatibilty if you open a presentation made with Showtime with another presentation SW, but is it a problem from the SW which created the App or with the SW you try to open it with?
It allows me to create presentations for my clients in a very easy way and access them when visiting my clients or giving a training session.
The benefits I realised with it are economical (Zoho Show is FREE) and practical as it shows in an instant to my clients the benefits of cloud based technology