Here is my subjective opinion.
I have my 600 for the past few days. It is not that bad. The advantages it offers me outweigh the reflection issue.
If you own a 505, you might strongly dislike the reflection on 600. This problem, I believe, is multiplied by one's experience with 505. I rarely notice the reflection on 600 but, too bad, am constantly reminded by 505 owners that there is such a problem. When I read on my 600, I have no problem. After reading those complaints, I start seeing the reflection when a question pops up in my head "Is there a reflection?"

(I guess it would be better for me to stay away from complaints about 600 screen

for the better).
If you have/had 505 or have doubts about 600 screen, 505 is likely to be a better choice for you.
More importantly, I use my 600 for non-recreational purpose. No kidding: It is more EFFICIENT for me to use 600, rather than 505 (I had 505 for a week and returned it back).
I love my 600 and am happy with it. My one cent

.