You lose all your weapons but I personally thought it was worth it for a permanent cash and exp bonus. If you use tons of different weapons all the time going prestige isn't your thing. However, if you only use a couple of weapons only, then go right ahead.
Once you've escaped the game's grind-intensive cycle, do you really want to look back and say to yourself, "let's do it again?"
The rewards are minuscule. Your +10% EXP, Gold, and +20 health bonuses, in the long run, make no difference for the first 4-5 prestige tiers. The Golden Skins, once a valuable and exclusive item, have become rarer than common skins Vengeance or Beehive. If anything, a prestige rank helps you get into a party better.
Prestiging was the active ingredient in me not playing R2DA, like, at all.