I've played at Morongo but I have not played in the tournament you are writing about above. I have played out in Palm Springs a few times, and placed fourth in a tournament at the Spa Casino, which I highly recommend.
The players at Morongo are typically way way way overagressive , to the point where they are suicidal and go AIPF with ridiculous hands out of position like KQo in MP1.
If you are 18 you basically have 2 choices (I think) in So Cal - Viejas in San Diego (which has a really fun bounty tournament) or Morongo, and definitely make it out to Morongo. You will find their tournaments fairly soft, and their 1/2NL game profitable if you play TAG.