I know of some folks that have attended Detail King training. Expensive yes. A major focus of their training is pushing their own products. There is nothing wrong with that, it is just their business model. I think you would get more unbiased training if you attend the 101/102 classes at AutoGeek. The focus is technique, not product pushing. Without good technique any product is worthless.
I attended Detail King's detailing class last May. The class was a 2-day event: day 1 focused on how to run a detailing business; day 2 focused on how to use their products and detailing procedures. I extended my training to a 3rd day which covered advanced areas of detailing. Of course they'll push their products. That's why both DK and AG are in business and offer monthly detailing classes.
For the record I use DK's products along with other manufacturers such as Gloss-It, Meguiar's, Wolfgang and Diamondite, etc. I'm not beholden to DK. I'll use anything I want or need (is there a difference?).
If anyone thinks Autogeek is unbiased and does not push their own products, take a look at who owns Pinnacle, Diamondite, Detailers Pro, and Wolfgang product lines. That's right, it's Autogeek's parent company, Palm Beach Motoring Group. As an open retailer (my term for retailers like AG, vs. a private company like DK) they have the luxury to sell what they want. I don't have a problem with AG pushing their products, although I find the difference between Pinnacle, DP, Wolfgang, Blackfire, Menzerna and Meguiar's product lines are starting to blur.
Since there are SO MANY different competing product lines available and my financial resources do not allow exhaustive testing, I am limited in what I use. Some of DK's prices may be high on some items but for the most part they're quite affordable.
As far as customer service goes, nobody beats Detail King. I've ordered items from Autogeek and they arrived within 3 days, the normal delivery time for UPS. DK products arrive in 2 days (they're closer to me than AG--a simple fact of geography) and I always get a follow-up phone call from DK to ensure my items arrived and I'm satisfied. Not once has AG called or emailed me to check on the order.
$250 may seem like a lot of money for a 2-day training class, but that's not much more than a 2-day session at AG. The biggest difference is DK will show you how to start and run a detailing business; AG focuses more on the detailing procedures and products. DK has a 3-day course that costs $995 (last time I checked), but that guarantees no more than 6 people in the class thus you get more hands-on time in the shop. The 3-day course also covers advanced procedures such as paint-chip repair, vinyl repair, carpet burn repair, headlight restoration, carpet dying.
Another big difference between DK and AG is DK will help you run your business; I honestly don't know if AG will, as I haven't asked. DK will even review your business plan (you have one, right?) and give you suggestions how to improve it. If you have questions about how to promote your business, DK will be glad to help.
If you have any doubts about the validity of Detail King's products or training, put together a list of questions and call Nick. Don't be afraid to ask him anything.