I had the 18-135mm and sold it. It's not a bad lens, but it's not a great one either. Whenever I was shooting something where I specifically wanted a longer focal length, the 135mm was rarely enough. Also, the 55-200mm has exceptional image quality. I shoot 90% of my photos with primes, but the 55-200 never disappoints me in sharpness or overall image quality. It doubles as a decent portrait lens too if you open up the aperture, zoom it, and step back a bit.
I would also say that if you enjoy landscapes, the 55-200mm is something I never go without for landscapes. It seems counter-intuitive at first, but a moderate telephoto zoom can get you great landscape photos in specific environments. I've shot the Swiss Alps with the 10-24 and the Cascade Mountains with the 55-200 and got great images in both cases. Excellent and underrated landscape tool.
