I think one huge plus for GG is that they do not allow huds. Times are more asian based which is great for day time in europe. Lots of micros at $2 - $2.50 and a few at $1, nothing under. Are pretty quick with withdrawls using crypto - around 48 hours.
Party has the most MTTs sub $1 by far plus have PLO and PLO8 mtts running constantly. They might not have the largest GTDs during the day but if I could only play on one it would be party. Took about 5 days to withraw last time to debt card
Pokerstars - big GTD and good if you like S&Gs. MTTs start at $1.10. I struggle on Stars in Mtts but run a bit better on S&Gs.
personally, as a micro MTT player would go with Party, the GG and then Stars - but if I included ACR and
888 would probably go Party, GG, ACR, 888 then Stars.