I found the screen on the lumia 900 made certain colors look really bad, for example in some games reds were really bright and looked almost neon. I find that the only good thing about the L900 screen is during daylight.
The other bad part about the L900 screen is in low light situtations (bedtime/movie theater) it is too bright even on the lowest setting.
One reason why the boards on the titan II are dead is because there aren't many problems with the phone.
For anybody who says that Nokia apps are better than HTC, I have to disagree, attentive phone I really missed when I had a L900, loved it on my HD7 and Titan II, the camera additions are built into the camera app. Those two are the best, and better than anything that Nokia has. Nokia does have some exclusives when it comes to 3rd party apps, ESPN app is horrible and I would just stick to the ESPN scorecenter app. The CNN app is pretty awesome, but so is the USA Today App in the marketplace. Nokia Drive is pretty neat, as it is free, but Bing Maps does the same thing, all you need to do is press the screen to get directions. the other part of about Nokia Maps, they should have installed it over Bing Maps on the L900, and Nokia Drive should be part of Nokia Maps as one app.
In the end, HTC Titan II feels like a more polished phone then any samsung device. There were too many issues with the L900 that I got I just had enough. HTC Builds quality phones, the enhancements are top of the line. The last thing about HTC, they were the last company to support Windows Mobile, I don't think the support issue is going to be going anywhere. I honestly think that they will come out with branding like (one s,x) type of thing for Windows Phone. Just like the branding on Nokia lumia, iphone (it is a brand), Galaxy, and Nexus.
If you do opt for a titan 2, I would suggest getting a case, the only bad thing is the camera does stick out. the cases that they do sell at the At&t stores should be enough to protect it for the most part. The phone does feel solid in your hand, feel premium.