I've gone back and forth on this one. The 199 PPI doesn't bother me. The OS doesn't really need ultra high PPI. My main concern was about glare, and the lack of Clearblack. I have seen all of the current Lumia 's now in person and here are my observations about the screens.
The 625 is not as bad as I thought. It doesn't have Clearblack (I use a 900 now) but it's OK. The reds appear orangish though.
The 520 is ok, but the lack of gorilla glass coating makes the screen feel a bit sticky, your fingers don't slide over it well.
The 620 has a great little screen. AMOLED and Clearblack. Bright and colorful. A bit small.
720, 820, 920,... All very nice.
I understand this thread is about the screens so I won't mention my other pros and cons. But for me, it's about the compromises you can and can not live with or without. Nokia has taken a different road than most others. Some pbomes overlap at a pricepoint and offer different things, unlike others where simply spendimg more buys you higher specs and a "better" phone. My hot buttons are the camera and screen. Screen size, memory, and speed, not so much. .