Ok - anyone on forum or comments will quickly notice a deep split in opinions on the Premium system. Some think its fair, and some don't. Both groups use numbers to back up their claims and... they use different numbers. Both are right! The problem is two different groups of readers.
Group 1 - the "average reader". These people read at average or slow speeds. A single chapter will usually take an hour or more to read and they simply don't have the time to follow more than one or two novels. The free spirit stones are calibrated to just about keep up with this group. For them - the system is fair. And it even encourages the occasional buy of a handful of stones when time allows for a bit more reading than normal.
Group 2 - the "fast reader". These people read at a MUCH faster rate than average. I happen to be one of them and... even the longest chapters on this site rarely take me more than 10 min. The shorter ones I can read even faster! I am perfectly capable of reading $1,000 US (hardcover new-release prices) worth of book in less than a week! This is why my book collection is almost entirely paperback and ebook. And even then I need to focus on library and free novels as much as possible. I'm currently following MORE than 100 web novels and webcomics on more sites than just this one. Nor is my reading speed unique.
Now - Qidan is obviously used to having lots of Group 1 customers, and little-to-none of Group 2. The problem is that much of their current customer base is Group 2 English readers who picked up Chinese translations out of sheer desperation because they ran out of other stuff to read! Their current spirit stone method is simply unreasonable for fast readers, very few of which would be willing to spend $4 a DAY to read everything they want. (I did the math, my current daily chapters would cost 200~400 spirit stones per day)
Interestingly enough... Qidan appears to have the exact same issue on their Chinese site too. Fast readers simply resort to piracy instead of complaining tho. Us English readers haven't done that.... yet. So far we are just complaining. Don't think it matters tho - Qidan doesn't want the money of Group 2 readers.