I don’t have GoCMS but do have Sentry.
To my mind, Sentry is best used on sites with a smallish CMS requirement OR where there are lots of text boxes that need editing, with some basic formatting and the occasional simple picture. It’s by no means a full blown CMS.
Go looks as though it can handle much more - photo slideshows, galleries, video and Soundcloud embeds etc.
I’m not saying you can’t do some of that with Sentry with a bit of tinkering, but it’s not really designed for that IMHO.
If I were you I’d also look at EasyCMS from Joe Workman. It doesn’t have the blogging features of TotalCMS but it’s a one off cost and - thanks to macros and great support from other stack developers like Instacks and Nick Cates - is surprisingly powerful.
Hope this helps - I’m sure others will pitch in.