I had an intermittent hesitation on starts (would not fire up first crank), turned out the air intake boot was torn in 4 places. Glad I found it before it kept running w/ a messed up AF mixture.

I replaced with Rein upper and lower boot (the lower boot was not torn but I changed both "since I'm in there") and did a quick cleaning of idle control valve.
The OE BMW pieces are made of a different material than the Rein. The OE BMW is like a rubbery plastic (NBV was printed on the piece) whereas the Rein is a soft-but-firm rubber ("PVC+NBR"), if this makes any sense at all. Also, the opening of the Rein pieces seemed to be a few millimeters larger in diameter than the OE BMW piece. Just ensure the hose clamps are tight.

Glad to report the hesitation at startup is fixed and the car is generally more smooth, which is expected now there's no leak after the MAF.