I'm on my 4th handset. I exchanged my 1st one only because of the call speaker was glitching. Then I went through 3 handsets in ONE DAY. All three were "Green Sticker" units which according to the manager at At&t were checked for hardware and software issues. Well all three, which includes the one I'm stuck with now have a horrible Vibra unit. It sounds like a clunking/metallic grind every time it runs. What sucks is the At&t employees agreed with me it didn't sound right, but the system wouldn't allow them to exchange another one, even though I had not even left the store with it. I contacted Nokia support via chat, they escalated my complaint and someone from Nokia is supposed to contact me around 230pm today. I'm also bothered by the Camera button not waking the phone from sleep, and the volume buttons not working with the lock screen, except for some music apps.
Pending my call with Nokia, and what they can do to help me; then will decide if I keep it or wait till this fall for a WP8 handset. My Samsung focus is twice as responsive as the Lumia 900, and everything works as advertised with my Focus, a Gen 1 device.:dry
Um, if you read the reviews on WPCentral, they specifically pointed out that the vibration unit in the Lumia 900 has a weird sound to it... it's probably not a good sound (I don't have one yet) but it's not a defect.
Camera button waking the phone from sleep is a setting. It's under Settings > Applications > Pictures + Camera > "Press and hold camera button to wake up the phone". Enable it and it will work.
Volume button opens the volume bar on the lock screen... what else did you want it to do?
I have a Focus too and I'm getting sick of hardware problems with Samsung. I had the motherboard replaced under warranty because it bricked itself (wasn't even updating or anything, phone just rebooted itself and died - no microSD cards used), battery wouldn't hold half a charge after less than 1 year (had to buy a new one), and camera is way worse than sample pics I see from the Lumia 900. Lately the new battery I got is acting up too, sometimes the OS can't read the charge properly. Once my power button died on me mid-day and battery discharged within a few hours (meanwhile the phone wouldn't boot up).
My friend's Focus bricked randomly too. He managed to re-flash it or something but later on the phone stopped charging batteries. It wasn't a battery problem because his replacement battery didn't work either and he had to sell it to me (which is working fine for me now). It happened just past the 12 month warranty.
It's not just a WP7 issue though. My other friends with Samsung Android phones have terrible hardware problems too. Dead spots on their touch screens (GS2), bricked phones, everyone's Galaxy S stock firmware lags badly, random reboots (GS), overheating, (GS) etc.
None of us are ever going back to Samsung again. Everyone is switching to iPhone, Nokia, or HTC.