The Vasque Summit GTX boots are really good, but they are a bit heavier than the Sundowners.
http://www.hermitshut.com/?product=vasq ... -gtx-bootsCheck and compare these sites, OMCgear and Backcountry tend to have a wider selection, but I find that Hermit's Hut usually has the best prices, and sometimes they're willing to special order in the products they don't carry:
http://www.omcgear.com/catalogsearch/result/?q=vasquehttp://www.backcountry.com/mens-backpacking-bootshttp://www.hermitshut.com/?s=vasque&post_type=productThe Scarpa Kinesis Pro GTX boots are roughly the same weight as your Vasque Sundowners, and they've had great reviews!
http://www.hermitshut.com/?product=scar ... o-gtx-bootAlso, if you liked the Wasatch, the Vasque Bitterroot GTX boots may be a great option to explore and they've gotten better reviews too:
http://www.backcountry.com/vasque-bitte ... -boot-menshttp://www.omcgear.com/vasque-bitterroo ... -mens.htmlIn terms of weight, the Zamberlan's are probably the lightest you're going to find, as they are only 2lbs 6oz. However, they aren't all leather...
REI has the best price I could find on those ones, and I think they may be running a sale on Zamberlan products at present:
http://www.rei.com/product/857258/zambe ... boots-mensSome people have transitioned away from Vasque boots, as they are no longer manufactured in Italy and are now being made in China. There have been mixed reviews about whether or not the quality is as good as it once was, however overall, they are still considered a great brand overall. I put the Scarpa GTX boots up because they are manufactured in Italy and are known for being great quality and long lasting.
I hope this information was helpful