It might be harder for me to put panniers on the CC because I'm short (5'2") and on the smaller CC frames you just start to run out of room. Not impossible, of course, just a little trickier than on a larger frame or the LHT.

I think the LBS's concern is that your handling is affected by a trailer and with dropbars your hands aren't automatically next to the brakes and shifters as they are on something with flat handles. This is also the LBS that will not let me test ride a bike with the kids in the trailer (they did offer to fill my trailer with heavy stuff to simulate kids); the other LBS has no problem with me test riding with the kids. So it could just be inherent conservatism/worrywartness on the first LBS's part.

The problem is that I want a sports car, but probably should get a SUV.

Edited to say, I have ridden them both (without the trailer), and I liked them both a lot. I loved the stability of the LHT and the plush plush ride on the crap streets around here. I loved how the CC could handle the crap streets, though not so plushly, and let you really get going.