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 version.
i don't have time to write a tutorial flight but I could help you with a short flight from dark and a transit setup. It is a beautiful simple aircraft.
i believe there is a PMDG tutorial for the ngx included in the install folder and flights taken from many different positions of the tutorial in the saved flights after install.
the PMDG 777 forum on avsim is also very useful for 777 operation although again not specific to the cs version.