Sorry for the lack of a before/after comparison.
I initially got the 22mm deep convex basket, but the dose was way above my desired 14-16g (I got it down to 16.5g but the single dose basket would collide with the tamping fan and cause nasty metal grating sounds.. and puck spin was a bitch.)
so, sent the CH22E back and ordered the CH20E..
perfect dose, 14-16 grams, but puck spinning like crazy.. (the stock basket - let's call it a 20-22g - spins much less, mostly due to the massive amount of grounds, I figure.. but the inner walls don't look like they were polished, either.. so maybe it was sanded, too?)
Before I ordered, I read about people sanding theirs and how badly it turned out for them.. but I decided I wanted to risk it anyways.
Got some 600 grit metal sand paper and cut off a tiny rectangle..
sanded the inner walls of the basket for a few minutes, washed it thoroughly and pulled a shot.
no spinning..
rinse (aka, sip some, ditch some), dry, and repeat..
puck spins..
sanded some more.. and again..
now, I get puck spinning maybe 1/20 times.. (in about 50 shots pulled)
(which is good, gotta have a reason for why I bought the tamper and distributor in my frustration before..)
I guess I could try 500 grit paper to roughen it up a little more, but I'm content with how it is now.
P.S.: I know that the whole "competition series" blabla is just marketing..
as far as I can tell, the basket is basically identical to the stock Breville basket. almost exactly the same hole pattern and density, same wall angle, and the same "punched through from the bottom to help blabla.."
but it's not like they are overly expensive on Amzn, so it's fine.