"You were recommended to me by my manager who took your class 5 years ago. The only way I can take 3 weeks long class if you were teaching that class."    ( Few weeks later: )  "Heinz, I got my number today. Thanks for the crazy weeks I spent with you."
CCIE 23044

"I highly recommend Heinz Ulm's CCIE preparation training. Heinz provides the finishing touches that one needs to be successful on the CCIE lab exam. Through his tutelage my skills were fine-tuned so that I was able to go into the lab without fear ( really, I was Uber-confident! ) and pass." 
CCIE 20503

"Thnx Heinz, You really are a special man, if I succeed, it will be especially of the way you have motivated me as a human being, sometimes the inner strength can make someone undefeatable.........."

"The class with Heinz was an outstanding experience, his exam hints and teaching technique made me very self-confident to take the exam right after the class."
CCIE 21033 on 1st attempt

I´m sure that i wouldn`t have passed the lab on first attempt without this bootcamp. Special thanks to Heiko, he really prepared us excellent! 
CCIE 22425 on 1st attempt

I can truly say: If you want to kill the beast with your first shot, Heinz Ulm is your only option. Heiko was my best teacher in 10 years of cisco network experience! 
CCIE 22423 on 1st attempt !

"Further I thank Heiko Gröger, a top CCIE BootCamp (www.heinzulm.com) trainer, who showed me that I had still much to learn to pass this exam"
CCIE 22371

 "I was lucky to meet and work with Heiko Groeger CCIE instructor at Heinz Ulm's legendary Bootcamp. Excellent location and infrastructure, Heinz'labs and methods are just perfect, personal face to face config check with Heiko were extremly usefull as well as interaction with others bootcamp students. 
I get my CCIE 20556 at 1st attempt one week after the bootcamp."