Ive had a different experience myself. Longshot has provided a decent amount of good critique and has shown a high semblance of skill. However, he is far from beginner friendly and even farther from allowing deviation from his own builds/etc. While I don't agree on all of his justifucations, he has shown quite the game knowlege in general and if questioned explains his decisions. He is hostile quite often but not often wrong, per-se. If you are stuck at a point of needing improvement but don't know where, id consider giving him a shot. Don't expect a nice coach, and do as he says, usually it should work out. HOWEVER that is not to say everything he suggests is correct, his knowlege is highly mathematical and sometimes he leaves out playstyle, and since his own playstyle is quite different from many players it may be of detriment to the learning player. Personally ive had good itemization suggestions, learning good items on certain characters and why current "meta" builds may not work. So much as ive had what I feel were "meh" suggestions, such as tiny trinket for early power on certain more aggressive supports. This ends up coming down to a playstyle preference, I have spoken out against it to a degree stating that I prefer the long term sustain that boots into pots brings.