Watching cdrama hoping to improve my mandarin to native speaker level. 

My rating system is based on math, so 5/10 is "average". I also try to be self consistent, because there are cdramas that occupy the 9/10 tier and the 3-4/10 tier for me. The factors that are most important to me are:

1. Plot: the script is the foundation of every drama and can make an actor's entire career (and we've seen this a lot in cdrama in particular). Many cdramas suffer from gaps in logic, bad pacing, and so on but it's improving especially in non idol dramas.
2. Acting: Although the industry is not there yet but generally, I try to use western standards for acting. Also the more types of emotions that the actor has to use, the harder the task is i.e. ML being cold faced the entire drama makes them look cool, but it's much easier than attempting to show humor, embarrassment, anger etc.

Because there's a tendency for inflated ratings on this site, and also a swarm of extreme fans, here are my beliefs about ratings:

1. Watching a cdrama is a huge time investment so I will drop within ten episodes if it's bad and I think this is the right thing to do. Because we need to have standards for what we give views to.
2. A drama is a work not a person, so just like a doctor can be judged based on their skill,  an actor should be judged on the job they do in the drama and this is not "hate".  We need to protect the freedom to rate the drama what we think it deserves based on our own judgement. The  fake reviews and duplicate accounts on here work against this purpose of the site. However douban is a bit better than MDL because there are way more neutral drama fans. Hopefully that will change here as well.
3. We can't use popularity as a substitute for quality or the standards will not improve. Evaluating metrics like views, heat etc. of the drama is cool and all but to me, the data is easily manipulated and fundamentally says nothing about the drama quality.