Well, I think it's fair to say that Bulking Up Steph is very well writing, at least for wg fiction standars. These guys that write fetish stories we enjoy and put some serious effort on it are not professionals, so of course you won't see a wg fiction with the literature level of Faulkner's novels; but that doesn't mean they aren't doing a great job.
Putting that aside, I think the story is solid and it has some amazing and vivid scenes. Some of the sex and humilliation scene are pretty explicit which I'm very fond of.
In the later chapters the characters of Joline and Delilah have grown on importance (and pounds) and altogether with a very hot main character make this story very worth reading, imo. The illustrations are good too. I can understand that some people don't like polaris writing or berserker illustrations but those guys are putting some effort on this one, that's safe to say.