Had to use Calc the other day due to an office 2010 bug in Excel that caused it to crash (doing a simple find and replace no less). Calc has always been there for me when excel wont work. Integration with Writer is better then in MS office.
Powerpoint, is way over used, and very limiting.
I have been using HTML online presentations, and I have been very intrigued by the way some people are delivering presentations using live web papge updates. You go to a web page at the beginning of the presentation and the content on the page changes with the presentor. Additional links and information are contained within, and to review in the future you just go to the web page. Additionally, if the content changes, if the presenter adds more information at a later time, you will see that when you return.
However, if you do choose to write a powerpoint like document in Libre, a simple script can update the title, date, and other information so you dont have to open it again if you are presenting in different venues or for different groups.