YES Level 54 (5th legacy) i had the best time going through the 5th legacy on this game I would like thank my really good teammates in Co-op and i would also like to thank Naughty Dog for making the past week double exp. now i feel like focusing on these stats
Co-op Completed Easy:33
Co-op Completed Normal : 25
Co-op Completed Hard : 128
Co-op Completed Crushing : 50
For me, it comes down to which mode you can max out (100k for coop versus 50K in comp) in consistently and how long each match takes (~30 minutes for coop versus 10-20 minutes for comp).
When ND has Cash/XP events, I can max out in nearly every coop arena match (pretty much every match when gaming with friends). In competitive, the matches are shorter but there are no guarantees - quicker matches usually mean less Cash/XP but in truth, I've never tried with the negative boosters.