Strange, seems like all the new phones take longer to repair. They must be overwhelmed with repair requests for the newer phones, or they must be having trouble getting more replacement parts or phones because I sent in a Lumia 900 and Lumia 920 on February 9th. Both arrived at the repair center on the 12th, but wasn't accepted into repair until the 13th. On the 14th, the Lumia 900 was replaced and shipped out, and I received it on the 15th. Meanwhile, the 920 was still being repaired/analyzed until the 20th when they sent me an e-mail saying they fixed it and sent it out. It's due to arrive today.
Also possible is since a lot of the Lumia 920 problems seem intermittent, it's harder and requires more time to diagnose/reproduce the problem. That, in addition to the other possible problems I mentioned above. In fact, I did send in my 920 for an intermittent problem, while the 900 was an obvious problem. Maybe that's why it took them an extra week for the 920.
So, does Nokia deserve my business? Well, the way they handled my Lumia 900 repair says yes. But for the 920? I'll have to wait to see whether they actually did fix the phone, since many people claim that Nokia sent them back their same phone in the same or even in worse condition.