When I first looked at the Lumia 900, I liked the matte feel versus the glossy white but my first Windows Phone was a glossy Lumia 900. I swapped out for a One X and appreciated the polycarb finish on the device so when I ulitmately became fed up with Android and returned to Windows Phone I got the cyan matte finish.
Cyan makes a fairly bold statement about you, your device of choice and I don't really want that kind of attention. To me it just says, look at me I'm out there, and I didn't want that to be my calling card everywhere I went. Would it have been a conversation piece wherever I went? Sure, because most people don't opt for a red/yellow/white/pink/blue/purple/mango/etc. phone, and basic black or silver work just fine. If gray matte was an option I would have gotten that when I purchased the 920, but the black seemed to me the more appropriate choice given the professional working environment I am in. I also didn't want the cyan hue to direct traffic to me much like the white Apple earbuds did when iPods were all the rage back in the day. I generally have enough on my person (phone, wallet, keys, bluetooth headset) to draw attention to myself from would-be thieves. I have never been the victim of a pick-pocket but I have had my car broken into before and lost things of value because in my foolish youth I left a radar detector out in plain sight.
The cyan 900 did have an unintended benefit though; when the 920 was launched my wife knew that this was the phone I had been waiting for so she agreed to let me add a line of service to our account and get the 920 provided I get a killer deal on it. On 11/7 when I pre-ordered the phone I didn't even pay the $99 + tax on it, so between my corporate discount and the $49.99 price correction credit I asked for and shared here on WPC I got an incredible deal. The catch was that our daughter would get my Lumia 900. So far I haven't regretted the move and I know that she is primiarly using the phone and PIM functions rather than surfing the internet. I also know that Nokia makes quality products and the 900 had excellent call quality and clarity. My wife sighs every now and then because she's on a Galaxy S III.