Even center tracks, while giving much more gap than other grooved bearings, narrow the gap by a considerable amount. I only find them usefull on yoyos with little wall for the string to rub against, making the slowdown during wraps not as important.
I have used many different types of bearings.
To be honest, no one bearing is better or worse than the others. (barring perhaps the old yyj and duncan bearings)
Seriously, if people focused more on actually playing rather than the equipment that they used, it would be a lot better. Don’t let anyone trick you saying that bearing x or y is better than bearing z.
Oh, and on centertracs, I have used them before, and to be honest, I don’t notice any difference in play when using a string centering bearing. Maybe this is because I focus on having a straight throw to begin with but seriously, I don’t see what all the fuss is about.
It’s a hobby. People are allowed to focus on whatever aspect of it makes them happy. Some people simply love the “yoyo as object” and/or engineering of a yoyo. Nothing wrong with that. You should listen to certain types of guitar players talk about their instruments, or certain kinds of technology lovers talk about their phones and computers! I think it’s a valid part of the hobby for some people, and one that others can easily disregard because it holds no interest to them. Neither is right or wrong.
Regarding center tracs or other string-centering bearings, I do tend to agree, though. You will notice the positive effects of “what they do” only if you throw a hard sleeper or breakaway and just watch it spin. Even on a good throw, the flat bearing could lend itself to having the string close to the walls; your yoyo will eventually slow down more and start to tilt.
But that’s if you sit there watching it spin; so while I do think there’s a benefit to those bearings, I think the benefit is minimized as soon as you start actually doing a trick. For me, I might sit there for a few seconds as I remind myself how to do the technique I’m working on. If the bearing helps the yoyo stay straight and fast as I futz around, that’s cool. But to me it’s ultimately not strictly “necessary”.
Id also agree… if doing so didn’t mean I disagree with a whole BUNCH of players i respect who are better than me 
I didn’t say there was none, I said it’s minimized (or more accurately, that I think it’s minimized… no pretenses here). In other words, it’s not a universe of difference (though there is obviously going to be an effect!) once in play; whereas a sleeping yoyo will quickly and dramatically show the difference. For the record (in case it wasn’t clear), I prefer center-assist bearings of any variety. Looking forward to trying some nice well-respected flat bearings, too, but thus far I have gone with center assist at every opportunity!
You know of course that the above quote is an ad-populem argument. You know that there are also a whole BUNCH of players who we respect and who are better than us who still stick to and/or prefer flat bearings. But that’s also an ad-populem argument. Neither is worth much.
All that matters are the facts, one of which is that the laws of physics demand that center-assist bearings like the Center Trac MUST provide a certain amount of benefit in terms of keeping the string away from the walls and the response.