Here's my viewed assessment - I see too many mid tones in the top image, and also in the ground area of the bottom image. These give the images an overall impression of being "flat" and even "lifeless."
I'd recommend beefing up the mid-tone contrast. I believe that will give these images more needed "pizazz."
Be careful not to wash out any more sky in the bottom image when working elsewhere within the shot.
FYI - Tony Kuyper, a knowledgeable Southwest photographer, has created some really nice PS luminosity masks which can be ideal for separating the mid tones. Here is a link to his site.
http://goodlight.us/index.html Visit his Tutorials, and read up on his PS actions for Luminosity masks, and especially the mid-tones. He does charge a $20 "donation" to download, but, in my opinion, it's money well spent. Of course, you can always make your own, but to have them downloaded as Actions, ready-to-go can be priceless timewise. And, of course, there are always other ways & means of dealing with mid tones.
Here's a link to some details on Tony's masks for midt-tones -
http://goodlight.us/writing/magicmidtones/magicmidtones-1.html