Saw a preview screening last night. No spoilers here, but....
Ignore the reviews. This is a well-made romp with a great cast that moves through it's genre-mashing paces at a good clip. The leads are perfectly cast and the supporting players are all perfect. The production is top-notch and it looks and sounds great.
Yes, it goes through it's paces in a somewhat predictable fashion and the one "gotcha" moment with a character isn't shocking and seen a mile away, but it doesn't stop it from being a great time.
I don't know what all the naysayers at RT are complaining about...it's called "Cowboys and Aliens", not "High Noon" or "Close Encounters"...with that pulpy title, you get exactly what you'd hope for....a bit of wacky with some style....
Big ole' thumbs up from me....