Ok, here's what I think after watching the video from Trading Concepts that they sent me, and speaking with Dan.
My personal opinion is that the income strategies from Trading Concepts revolved mainly around trading collars.
What I didn't really like was the many speculative type strategies taught compared to the number of income strategies. There was also a testimonial from one of John's students on the video which essentially says how much money he made in one trade, and this guy had only been trading for a very short time, and is already trading a big account. This troubles me, as I know it takes time to learn the skills necessasry to trade for the long term successfully. I have the feeling that if it were Dan, that kind of testimonial will not even be in there.
I might in future consider spending the money to go learn from John, if only to add a few more workable strategies into my portfolio. John unfortunately does not have the kind of track-record, training and real life trading experience that Dan has.
On to Dan. Dan has 23 years of pit trading experience as a specialist on the CBOE floor. His credentials are verifiable, and impressive. I would say that to be able to be a market maker in the pits, you must definitely know at the tip of your fingers, what you're doing. You have no choice over what to sell, or buy, as customer orders come in. On top of it, you also need to be profitable. No easy task I think.
With that kind of real life experience, in-depth knowledge and doing it for so long, I believe Dan's strategies should work better than a lot of others out there. And learning about them on the webcasts, they make a lot of sense to me. I had a few questions that I asked him, and his answer removed my doubts about his methods, he's very careful with money management and keeping losses small. I believe that is crucial when trading strategies like the IC.
On a personal level, my gut feeling is that Dan is a very sincere, honest and patient guy. (Edited to add: He's nothing like the bigger-than-life, highly extroverted character he portrays in his webcasts!

) I feel that he sincerely wants to help his students be successful, and that he wouldn't be doing this if he didn't think it could make them successful. Furthermore, from what I understand, his old students join his sessions on Friday night doing live trades, and trading big contracts. If his methods didn't work, I'm sure they'll bring it up by now.
Dan does say that he does modify the details of his methods through the years, but the philosophy and the core ideas stay the same. His opinion was that in all the years that he's mentored students, the difference between those that succeed and those that didn't were not the methods he taught them. It was themselves. Either they didn't follow the rules, they weren't strict with money management or they just got greedy (after a few winning months) and traded way too big too soon without gaining the necessasry skills and experience, and couldn't take the losses, then give up.
I'll definitely be going with Dan's course. Thanks to everyone who contributed and shared your experience, pls feel free to share further if you have any thoughts.