How to ask a group of people "What do you think? in Spanish?

How to ask a group of people "What do you think? in Spanish?
 

What is the appropriate way to say "What do you think? when the question is directed to a group of people? Is this correct: ¿Qué les he parecido?

¿Que creen uds?

or que les parece

"¿Qué les he parecido?" is asking something like "What do you think of me as a presenter?" and not "What do you think of my presentation?".

If you ask "¿Qué les ha parecido?", you are talking about the content of your presentation, or other thing, like a movie or a play "¿Qué les ha parecido la película?", also "¿Qué les pareció la película?" in the Western Hemisphere.