We implement BC sites for our web design clients on a regular basis. It is used by the Web Design and Development division of our company as one of several go-to options for CMS. We also use it as the platform for our corporate website. We use or have used almost every feature in Business Catalyst in the time we have used it across 30+ client sites.
There is a lot of documentation out there, but much of it is out of date or lacking in detail or specificity.
The biggest weakness of BC is its support. While the chat feature is good, it has long hold times and staff that is not knowledgeable about the product. I doubt anyone in support has ever even built a site with Business Catalyst before. They need US support centers with actual designers or developers who would be able actually help. It seems like 50% of our support questions should be easy but end up being escalated as a "not for the development team" or never answered.
The Admin UI could be more intuitive and the In-Content Editing is very difficult to actually use in practice with a novice client.
As someone who uses it on behalf of other clients, our ROI with BC is definitely positive. We needed a mid-range CMS without huge licensing costs to satisfy mid-range clients who have some dynamic needs but doesn't need the expense or liability of enterprise level products. Without it we would have lost possible customers or taken bigger hits on projects because of the costs involved with satisfying their mid-level needs
Our clients are all usually very positive about the BC platform and are able to use it themselves which lessens our Support time/cost.
To use the Web App element,. which we do on almost every site, you need to pay for the highest plan. This brings along with it many features most of our clients would never use. A more basic plan with that Web App capability would be a big improvement on our costs.
Adobe Business Catalyst has Web Apps which makes all the difference between them and competitors. Without that, BC would be behind many of the other CMS systems out there. Being a hosted system without any maintenance needs also puts it ahead of others. LightCMS is easier for clients to use, but not as customization and Evoq or DNN is over complex but a stronger platform..
Adobe Business Catalyst is perfect when you need to create a data driven element for a site. The Web Apps element is great and not something other hosted CMS systems have. It is also a good product when someone wants to make use of multiple modules in one place such as having your website, CRM, online store and email marketing in one place. BC is fine for small sites, but is a bit over complicated and over-priced for a basic brochure-ware type site without any dynamic features. It also does not allow enough customization for a large enterprise level site with a demanding client. As a hosted solution, it has no ability for server-side development or other customization that might be needed on a very complex custom site.