I like the 737 ngx from PMDG, but I have used it only in fsx. I know of no issues really in p3d v2 but I haven't seen v3, especially v3.4.
it is quite a resource heavy aircraft but I used Matt Davies settings for a320x from fslabs (check you tube-it's for fsx) and It gives me usable rates. Better than the PMDG 777 not as good as the majestic dash. Although that isn't entirely useful.
if you have specific questions regarding the operation of the cs 777 I would be delighted to help. I don't have the cs version so I can't help with their interface but I do have knowledge of boeings vers