I think the proper term for these belt factories is called "mcdojos" applying to TKD and karate. Grandmasters are 8th - 10th degree blackbelts and are around 30-40 yrd old. I've seen a few where the head instructors are obese and explaining things to you and the thought could be in your head that taking advice from someone who can't even scratch his back is not credible. One dude here where I live when i visited a karate dojo SERIOUSLY looked exactly like Tank Abbott. Anyways, some places make you sign a 6-12 month contract and if you can't make a payment they send a collection agency after you...and also tuition is like 180+ a month..but if you spend enough time consistently at these places you can get into some decent shape with all the sparring, but is it quality and will they work in real life situations when you've been practicing stand up point sparring and minimal groundwork? that's for debate. and with that consistency you can be a blackbelt in 1 1/2 - 2 years in certain styles. I think belt tests are great if you really earn them and I don't mean by learning kata...proving technique you've learned and applying it..