Just before leaving for a trip to Colorado, I took a deep breath and bought a new lens. After reading rave reviews by several photographers whose opinions I respect, I invested in Canon's EF 24-105f4L IS lens. What a joy to use. When I first began to flirt with the idea of buying this lens, I almost balked at the price. I should have known better. When I bought the 70-200f2.8L, I had the same issues about spending the money, but learned then that while L stands for "luxury item"—meaning you can't include it in the list of essentials, it makes a dramatic difference in the quality of the raw files I capture. That results in less time processing and that means more time can be spent taking photographs. That's a big win in my book.
By the way, the photographer who most influenced me in this decision was Paul Butzi. If you have never visited his blog, it's a treat. You can find him at: http://photomusings.wordpress.com/