I've explained downgrade timestamp feature in here:

http://forum.meego.com/showpost.php?...&postcount=201

Well, after i have flash lasnight my new n9 16gb black singapure product code 059xx .005 to swiss roduct code 059xx .009 sucesfully, i see diference a lot, some bugs i encontered like "app.name? doesn't respond, stop yes or no"eny of them i lounch the request did pop up a sec or two...now is goon, the battery critical status is goon to, the wi-fi signal weeknes now is better and bit stronger, the screen diming and mismatch touch calibration is goon to, but also my phone pics,music, docs and videos was wiped out during flash as i fllashed both big files....but i know that i should make backup of my files prior flashing proces...all i can say, i fell like i ben updating to v.1.4 not just v.1.3!
I will have to see of what more changes have hapen to my n9.

These differences are probably due to variation in hardware components. For example Nokia had several suppliers for N9 AMOLED panels. I have one N9 with a screen that has warmer whitebalance (slighly reddish/yellowish) compared to another that has it's white balance spot on and is brighter overall. Both phones have the same firmware, but screens are clearly different.

Latter parts of IMEI numbers on the phones are:
2354235, N9 16GB, cyan (reddish tint)
5093798, N9 16GB, cyan (good white balance)