I like 'em. When one of the first poly RNTs came my way, the two then-current acrylic darlings of the speck calling world I was alternating between both went down the road, and I now own two acrylic RNTs: one that's on the lanyard and one to experiment with reeds and their tuning. That said, I've been running calls with much the same working dimensions as the RNT since 1983, so I'm quite comfortable operating calls with what are now considered "small guts".
The trend now is toward "big guts" like those used in Redbone and Riceland calls. And while Jason Cambell managed a 2nd in the "Worlds" against them with a $10 poly RNT some years back, big guts now dominate most competitions and have set the current tone standards for them (at least to my tin ear). An oft cited advantage to big guts that I'm now inclined to agree with is ease of use. They're apparently more forgiving of back pressure variance. (Saw that for myself when a little farm release gator tore up my index finger, which I wouldn't think critical to back pressure, and I couldn't run an RNT with the wound but had no trouble with the Riceland that shares the lanyard with it.)
As to field application, each type is setup to have it's own tone and volume advantages, and whether I use the Riceland or RNT depends largely on where I am, what the birds are doing and what other hunters around me are doing.
If you think I'm wrong, you might be right.