I have personally installed, administered, and used Geocortex Essentials in a enterprise setting and it is a fantastic product. At the time, we were just starting to deploy ArcGIS Server web apps internally and we had to choose to go one of two routes:
- Roll our own custom applications (WebADF 9.3.1 at the time) and build the functions our clients needed and wanted - and they wanted it all yesterday (print, create reports, etc.)
- Buy a product from someone else, install it, and leverage those functionalities, plus get support
Once we saw what we got for the money from Geocortex Essentials, we knew that there was no way our 3-man team could roll all of that Essentials offered for what it cost. Plus, we had other things to do. That combined with the low cost relative to our business (Geocortex licensing is chump change compared some enterprise licensing like Informatica for instance), the responsiveness of the Latitude business team, and overall performance of the product made it a no-brainer for us. That said, you are a small business, so licensing costs look different to you that they do to a large corporation, I understand that.
As far as what it can do for you specifically, that sort of depends on what you do, and you might not be able to discuss that here (if you can, please elaborate on that). I would suggest calling up Latitude Geographics and getting a demo setup with them. They are extremely easy to work with and have a great sales team.