The truth of the matter is that you never know … until your guest speaker says “thanks for having me,” and he/she walks off the stage. Regardless of who you select to spice up your meeting with a little outside information, it is a crap shoot.
There is one way to stack the cards in your favor. And it has nothing to do with glowing testimonials or pretty websites. It has everything to do with the way you perform your due diligence.
Call the candidate. Talk with them. Tell them exactly what you expect, and then ask them if they think they are up to the challenge. If you call me, I promise you that I will tell you the truth … whether I believe I can help you or not. 848-702-1009. 
Any speaker worth their salt will not set themselves up for failure. They will either tell you they can; they can’t; or they know of a better choice given your set of circumstances.
The only words you want to hear as a meeting planner or program director following your guest speaker’s segment of the meeting is “Thanks for bringing in XYZ.”
Let’s have a brief chat. What can it hurt? 848-702-1009