NWBIG means "Not Worth Buying In Gen" as in, the rep is good enough in appearance and quality that it can adequately stand in for the gen under nearly all circumstances. I am only about 6 months into buying reps and have about 15, but I can say for sure that the ones I have bought are definitely worth what I paid, up to $600 in one case. I mean that just as a watch. Add to it that it's standing in for an 8K, 10K or 35K watch and we got a freaking bonanza going on here.
I have chosen to stay with ETA movements (2824, 2836, 2813) except for the landmark Noob Daytona 4130 and a Miyota 9015. I can work on the ETAs and the Miyota myself, they are fairly simple, cheap and easy to replace. Many of the Asian super clones (3135, 3255, 3186, etc) can be more troublesome and are harder to get parts for and to service, etc. For every post I see with an ETA issue, there are 5 or more about a super clone. Some watches are only available with a super clone, for me that most often means choosing a different watch.
Here is what I chose for the 39mm Exp, a cheapie from Reg with a 2813. $105, pretty much the best bang for the buck I ever spent. Good luck with your choice!
