For my part, the two pairs I got sounded the same. The one has a very stiff adjustment mechanism on one side, though. I didn't notice bass decreasing, but it became less boxy-sounding. Can't say I find the bass is lacking at all. I did take the sticker off the hole on the back of the driver and enjoyed it for a bit, but did find it sounding one-note-ish. I didn't look after my removed stickers very well and so landed up replacing them with this papery material from inside a bag I tore up for its leather that seemed very close in consistency. Sounds great.
If people wanna open that sticker just a little,I was thinking that a proper medical-grade needle, 22 gauge or so, would be a better option than the pins we tend to have at home. Can try the smallest of holes to increase bass. I know it's recommended that you don't damage the stickers so you can put them back on if you aren't happy, which I did and then promptly messed up the stickers anyway. For warranty purposes it might be an issue, I guess.