I am very familiar with all of these poker variations that you have listed. I have played live Hold'em, Omaha 4 cards, Omaha 5 cards and Courchevel. All these 4 varieties of poker are completely different, the tactics and strategy of playing them are also different. Courchevel is interesting in that it opens one card on the flop, and then the first round of betting begins. If I am considering a game to make money, then I will definitely choose Holdem and in rare cases Omaha 4 cards. If I just want to have fun, then I will choose Omaha 5 cards or Courchevel. All these games are interesting in their own way, their difference is in dispersion. Online I played Hold'em and Omaha 4 cards, I did not play other varieties of
poker online. I live in a small town in the South of Ukraine, we have 3 poker clubs and in one of the clubs at one time we played Dealer Choice, the player who was on the button could choose one of 4 games.