I've owned Novak, Tekin, Castle, LRP, and have had to send ESCs back to each with problems, but Novak and Tekin had the best customer support hands down.
I've had four Castle, four Tekin, one LRP, but I finally settled on Novak and I'll tell you why. If anyone has ever watched 4x4 SC racing and seeing Novak's little controllers doing the job of a bigger RX8, it's impressive. I was able to shave 60g off the weight of my SCTE going with a Novak. What impressed me more is the temperature of the GTB2 was always under 115F! It never broke a sweat. Then I began to experiment with the Havok Pro and found I simply didnt need the PC anymore to have an aggressive timing profile that I like.
Now maybe I'm lucky, but I've only ever had one Novak controller fail on me, and I've owned seven Novak controllers. I can count on their equipment come race day.
Now if we are talking brushless motors, I am definitely partial to Novak. I've owned motors from most of the manufacturers too, but Novak has always had some of the highest power, if underrated motors in this hobby. I own a brushless motor dyno (The McPappy dyno uses the spreadsheet I helped create), and found the claims of many motor manufacturers to possibly be inflated. I remember Novak claimed around 165W for their 13.5 and hacker comes claiming 300W. Running them both on the dyno I found Novak producing over 200W and the hacker comparable within 5W, but with less RPMs and much lower efficiency. Look, to give Hacker credit, maybe on their dyno it appeared to show 300W. Not all dynos are the same and my dyno and power calculation method differed from both Hacker's and Novak's methods.
Everyone here who has had a Novak fail can't say that Novak didnt stand behind their product and try to make it right.
My bulletproof GTB2 was actually one that had the backwards cap problem, but luckily for me I'm an electronics engineer and noticed it right away when I began to make modifications to my particular setup. That GTB2 is still powering my SCTE to this day.