Center-Trac come clean, CTX come pre-lubed. If you got a 25-second flick, I wonder if that was new from the factory or if it had a stopover somewhere?
As for string centering, a lot of people have a lot of strong opinions, but in MY opinion they’re overstating the case. It’s not going to ruin you as much as you think, and it’s not going to help you as much as you think.
People also talk about this “string bunching” because it’s intuitive. It makes sense to imagine that your string’s going to get all bunched up if it’s forced to the middle. But nobody has done a study, and after my own experiences, I don’t think it’s as big a deal as people think. It’s like the opposite of a placebo: people imagine it will hurt, and so every little bit of friction or every snag, they want to blame the bearing. I haven’t done a study either, but I’ve looked carefully and I’ve noticed that profiled bearings still tend to allow the string to move out of the way for new layers. Less effective are the grooved bearings, but the loop can still “pop out” of the middle most of the time. Very effective are the new Whippel bearings (JD’s “signature” bearing).
Think about this, too: with a flat bearing you might avoid “bunching” to a certain extent, but you will also cause your strings to touch the response pads more quickly. That “bunched” feeling can happen when your string is being dragged against the response even moreso than when the string is being dragged against itself. Now, this can be a benefit. I do think that you will get tighter binds on a flat bearing, and your trick binds will have a tendency to work better. So this higher response is not always a bad thing.
Anecdotally: I had one time where I kept getting snags and bunches and thought, “DARNIT! Everyone is RIGHT about this! Forget profiled bearings!” and went to swap out my bearing. Only to discover it was a flat bearing all along.
Suffice it to say, people talk a lot, research very little, and present intuition as fact.
I think my favourite bearings are all flat bearings-- OD 10-ball, Northern Spin CORE, and Gen-Yo AIGR. But I like that new Whippel, enjoy Trifectas a good deal, and one of my best combinations is a Supra with a KK. Very rarely do I attribute either success or failure to the bearing. My technique is much more of a factor.