It's really tiring and completely baseless. I went to sky4u for only MCC. Had an incredible time and learned a LOT. The cost/benefit is out of this world. Lufthansa training center is really inspiring and at my Ryanair assessment they really liked the fact I went there. I have a friend there at this exact minute that went from my recommendation and is enjoying it immensely and another lined up for right after his skills test in Oct.
Not enough could be said about the instructors, getting tips from former or current TRI or TRE with years and years airline experience does wonders for the next step in your career.
I will continue to debunk them everytime they post because I almost didn't go thanks to their negative spamming. I'm sure I wouldn't have done as well as I did at the assessment if it wasn't for sky4u.