Just to throw another thought out there. Tires play a pretty huge factor in the sluggish feeling. Sometimes simply investing in a higher quality, higher thread count tire will make a huge difference.
We sell LHT's and CC and will have the straggler as soon as they come out. We work with customers who are often in your boat. The Bike Hermit's commuter is a CC, he has an extremely large Paul Basket on the front and loves it. He also will pull the Bob for large package trips to UPS. However when loading up the bike, he prefers the LHT for stability. I personally love the ability to descend with confidence on the fully loaded LHT.

Okay back to tires, Consider a decent width for more comfort and road shock absorbing issues. We encourage at least at 32 (regardless of rim size) I ride 40 X 650B. We love the Schwalbe Big Apples for commuting and touring. Given that I have 650B wheels I ride the Grand Bois Hetre's and I was totally amazed at the difference when I put them on Sky. They just roll and roll I came off of the Rivendel Maxie Fastie's and the Hetre's kicked butt

ps, as you can see in my photo I ride these extremely smooth tread tires on dirt and gravel as well as smooth pavement.