I'm a little late, but I'll toss my opinion in here anyway.
I've been living in China for about a year now, and I love what Rocket Chinese (RC) has done with the Premium Plus course. I'll admit that Lisa sounds as if she is reading right from the script, but I can get over that. The best thing RC did was to bring in Tao and speed up the script.
While the RC Premium course is necessarily slowed slowed and pronounced almost overly clearly, at some point you've got to start speeding things up and getting closer to how people actually talk, which is the direction the RC Premium Plus course is going.
In regards to Tao's gravelly voice, it's been my experience that many Chinese men sound exactly like this, and I think RC would be doing us a disservice if a native sounding male was not included. I note that smoking, particularly among men, is very common, so perhaps this accounts for the gravelly sound.
I was also pleased to see, well hear, that Lin now sounds more natural on the RC Premium Plus course. In addition to speaking faster, she no longer pronounces everything with seemingly unnatural clarity.
Ultimately, while I am forced to listen much more closely now to the RC Premium Plus tracks, I feel like I'm actually starting to pick up more of what actual speakers around me are saying.