You'll get a bunch of people who'll tell you something close to the truth, and that is the people behind KTA dont trade, cant trade, and have nothing to offer that cant be found free of charge on various forums. They might even post you links to various places where KTA have been exposed / critisised etc.
Unfortunately a lot of those negative (but truthful) posts will then get deleted by the moderators here for various reassons.
Then you'll get a bunch of people posting claiming KTA are the best thing since sliced bread (some may be genuine KTA clients and some may be shills or affiliates paid to market thi product, and some may be mischevious rogues posting 4 d lulz)
Whatever you read, you cant really trust their advice. Did your collegue attend the course ? if so, it didnt work if he's still in full time employment.
If you've decided to waste 3.5K on a KTA course then noone's going to stop you, but if you are still undecided, I'd advise buying a few books, open a demo or a small account somewhere, and try to work things out for yourself over the next 6-12 months, THEN re attend a seminar, and see if it makes sense at that time (hopefully it wont, and you'll be able to evaluate whats being marketed more objectively)