Hidden Content - Using CSS and Javascript

On of the biggest problems, I'm facing as an SEO expert inside an agency is getting stuff my way, the SEO way. When we first start working on a project I always get into some contradictory arguments with the designer over hidden text, later on, I have the same problems with the programmer. 

They always want to implement the fastest solution or the "trendiest" idea and this isn't always good for SEO. 
So when do we need to implement hidden text with CSS or Javascript and when do you need to keep everything in the open?
First of all, Google admitted that pages that contain hidden text, that can be seen with a "read more button or other CSS/Javascript configuration will always get slightly lower rankings compared with a full shown content on a page. 

• Implement hidden text features ONLY when the benefits of having such a feature outweigh the actual SEO potential. In other words, if implementing such a feature can bring your more benefits, like conversion, design related optimizations or a better user experience you can go ahead and implement hidden text. 
  
• When you have enough visible text that contains SEO ranking factors like keywords, subjects and enough content to beat the competition. 

More information regarding this subject you can find here. An extended SEO experiment made by rebootonline.com's Shai Aharony
The result and conclusion of the above experiment are pretty clear: Google prefers visible text over all other alternatives, including hiding text with CSS or Javascript.