SOME FACTS before we all go off half cocked:
1. 335i on e90 have reported wastegate ticking issues (search and you will find many post on the issue). They rattled and eventually had to be changed.
2. N54 wastegates on pre v29.2 were closed and thus the engine was spooled and ready to go.
3. Theory is that the "suspected lag" is caused by the wastegate being opened by v29.2. This solves the rattle. So the hesitation is from closing to spool up the VOOM.
CONCLUSIONS:
1. Nobody can prove that the "suspected lag" existed as there is no definitive dyno proof of the problem. It's all "butt dyno". I do think that there is some hesitation though.
2. There is NO PROOF that there is a loss in power from the suspected hesitation.
3. There is NO PROOF that the 135i has the wastegate issue or v29.2 fix in it's software.
I suggest anybody who is breaking in their cars wait to check to see if there is some lag. WHY...because you are going to feel some lag until you WOT your car.
imho there will be MANY other issues with v29.2 followed by v29.xxxxx fixes that we will all be speculating that BWM has screwed us somehow.
JUST DRIVE IT and have FUN.
For those that really want to read and keep up with the latest facts/speculations, I suggest to read all the post relevant here:
http://www.e90post.com/forums/forumdisplay.php?f=58