Who cares what works and what doesn't? There is no replacement for table time IMO. Systems, whether aiming or any other form are of no use without enough time practising them. There will never be evidence of whether this time spent practising improved a player purely because they put in lots of practise or whether they improve because they spent time practising with a system.
From my experience they appeal to beginners and those looking for a way out of admitting they haven't been paying much attention to how balls react. I can get 10 new comers to pick out the ghost ball position after 5 mins of explaining it. Aiming isn't hard.
I don't see CTE as an aiming system. It is more of a PSR for getting a person aligning correctly. It sets them up so their body is aligned following some guidelines but the actual player aims the shot, CTE just gets them close enough to the line of aim for them to spot it.
Lots of players struggle with repeatable alignment, even those at the top of the pecking order. There is no shame in it, it's difficult to imagine where your grip is, hips are and so on along an imaginary line without looking at them. Feel players especially struggle with alignment. They tend to spot the line of aim and just get down and have footwork that's different shot after shot, they preach the cue ball from all kinds of different angles. There is no better or worse in these arguments. There are pros and cons for both. But people making claims like it makes them aim to centre pocket every time are living on cloud 9. I see players shopping balls in a diamond down the rail using CTE. That isn't centre pocket but I'm sure someone will develop and argument as to why it is doesn't matter and how it was the shooters fault.
I have a friend who is one of the best cueists I've seen that isn't a pro and I gave him my 1st DVD to take a look at. He was shopping balls on left right and centre and missing shots on a snooker table he would never miss. Why? Because he followed the instructions too literally. He forgot all he knew about pool and snooker and focused on what the system tells him to do. He gave it a good 6 months before he gave up. 6 months is no where near to learn real Cte, pidge! For someone of his skill level it is. He had a decent potting percentage with it, probably in the 75% region on a snooker table. He had 87% potting average in the 5 tournaments running up to me giving him the DVD. For someone with a near perfect cue action 75% is terrible IMO. He found playing with side a nightmare, this is why I say it's for beginners. You can't get anywhere near the top without using side effectively. He definitely took a step back in his level of play. Why? He had no alignment issues before. Cte caused him to align differently than he had been doing for decades. Not that he was aligning wrong with Cte it was just not what he way used to. Again, this is why I say it's for beginners or those struggling with alignment. If a newcomer doesn't know how to align then it gets then aligning a bit better.
Lastly I know I may get abuse for my post but it is how I feel regarding the matter. I don't expect people who think I'm wrong to lay down and take it, I respect people who stand up for what they believe, especially if they can do it in a logical and civil manner.