IMO No, its not.
there are still too many features missing. wolpacks (real wolfpacks), more communications, better sub handling (batteries etc.), crew shifts/management etc. etc.
GWX cant implement that, no mod can, because of the SDK thing...
but GWX is still the best what you can get for SH3 i think...
maybe it will be possible to "transplant" a few features from SHIV in SHIII...