There has been a huge amount of chatter on this one over on Facebook. I'll summarize, and add my own opinion.
So, we have a high risk, HUGE reward card. Naturally this leads many to consider, is the risk to great, can it be mitigated, and is it worth it.
First, discarding a dude if a cheatin' card is used against you is bad, quit possibly game losing bad. The biggest fear is getting a cheatin' card played against you for lowball, since there is not much you can do to stop that. If you won previous lowball, and have a quick draw handgun in play, you can prevent your opponent from playing a cheating resolution of they are cheating as well. Henry Moran can do a lot to save your bacon, but that's not guaranteed. 108 Worldly Desires tends to cheat very infrequently. The Extra Bet, could really help with not cheating in lowball. Also, if your winner of the day, and have Willa in the shootout, you can ace her, and send your dudes home booted before your opponent can play a cheatin' resolution.
Also to consider are dudes that you don't plan on keeping in play. Bobo, and Steven Wiles with The Gambler's Gun are massive threats for only 2 gr and 2 cards. Mortimer Parsons is another interesting dude to put it on, since if he is alone and cheats he will be sent home immediately (with penalties) ending the shootout before resolutions can be played.
This card could be very good with Putting the Pieces Together in a deck that doesn't cheat very often (like 108 WD)
This card also becomes extremely powerful in bicycle format (or near bicycle standerd). This gun on Mario Crane, and your looking at causing some pain.