Dear god, no. They are a basically a cult.
The main argument against them is that they are incredibly sectarian and very closed off from the rest of society, to the point of telling their members to avoid contact with non-communists, im not kidding. Im sure most of you guys can understand why this is a terrible idea, and the only objective of such advice is to create an echo-chamber inside the organization in order for the people at the top to do whatever they want inside of their little kingdom. This tend to a lot of paranoid opinions and behaviours in their ranks, which added to their heavy emphasis on self defence and martial arts (mind you, their GS is a martial arts teacher), has lead to some very nasty accusations agaisnt them from other communist organizations. I dont know for sure if they are real, though, but I woudn't be surprised.
Politically, they are known for their main organization strategy, which is to create "front" organizations -this is, organizations that focus and struggle on a particular issue, in order to get in the ranks people and collectives from the popular classes affected by those issues. e.g.: students' unions, neighborhood associations...-. The problem with their approach is that they create phantom organizations, empty shells which claim to represent a lot of people and big issus, but, in reality, they have no people inside other than the militants of the PML(RC). Basically, they start from the top, and then try to fill their invention.
A few years ago they tried to get attention from the main public by sending two guys to Syria, in order to fight with the MLKP and the YPG, and it was a success. Only problem being, they got caught on their lie pretty hard, and it was discovered that they basically went to make revolutionary tourism, and thet they neither saw any combat nor worked in other areas to support the YPG.