The single most confusing and misunderstood home, by far. I also think it is the most under-rated.
Quick guide on the React (because the GR reduction part is straight forward):
Let's break it down.
"After you complete a Noon or Shootout ability that moved one of your dudes, draw a card and discard a card."
This makes sense by itself. Any time you move your dude with a horse, whether it is a noon action or you are booting your Pinto to join your posse in a shootout, you can use this react. Note, though, that it doesn't matter what causes your dude to move, as long as it was your ability. That means cards like Railroad Station, Surveyor's Office, A Secret Tunnel, and even Flight of the Lepus (if you choose your own dude to move) can activate this react. This does not work if you use your Pinto to join a shootout at the same location, as your dude never actually moved locations.
Then you immediately draw a card and discard. If you move your dude and can react, there is almost no reason NOT to use this react so you can at least cycle one card. Remember that you draw first, so even if you like your current hand you can always discard the card you draw if it isn't better.
Next, and the confusing part:
"Make another play or pass; if you are not in a shootout, that play cannot be actin’."
If you are in a shootout, this is straight forward: you either move your dude into or out of the shootout, and you get to immediately do another shootout play. That means this react turns Pinto into a Shadow Walk, where you can boot in and immediately shotgun a dude, if you are able, and the opponent can't stop you (short of a A Slight Modification).
If you are not in a shootout, you get to make another noon action after you move your dude with an ability (whether its an action card or a horse or a deed ability, etc). There are 6 choices for Noon actions: 1) Actin' 2) Callin' Out 3) Movin' 4) Shoppin' 5) Tradin' (we hate the letter G in the Weird Wild West...) 6) And Pass
Your next play cannot be Actin', so that means you can do any of the other 5. That means you can use your Mustang to move to a location and immediately call out a dude (who, if booted, of course must accept). Or you can use your Guide Horse to move to the town square, react, then move again to any adjacent deed before your opponent has a chance to call you out in the town square.
This allows for some very powerful surprise moves, and if you are playing against a Stables deck, you have to always keep in mind these possibilities. Any booted dude anywhere, except your home, is subject to a call out. Even if they don't have any horses on the board, you have to keep in mind that your opponent could simply be waiting for you to boot a vulnerable dude, at which point they then play their discounted horse and cause havoc.
My favorite use of this is to wait until the opponent uses their Allie Hensman, then equip a shotgun and Mustang and if I am the winner, that is a dead Allie. Only A Slight Modification (not likely if they have Allie) or Pearly's Palace can interfere. Best to wait until you are the winner to do this, of course.
I've also found that many times I will simply pass on my 2nd noon action, since I was just using the ability for the card cycle, but remember if you do that and your opponent also passes, the turn is immediately over. Go Shoppin' or do whatever else you wanted to do instead of passing if you don't want the turn to end.