I just managed to ride it for 5min around the neighbourhood. First impression is that is feels great. I look forward to riding it more though!
Oh, what good news you have the bike in-hand, but what agony to have to wait to ride it! 'Makes the minutes crawl by, I know. The good news is, your first impressions are good and will likely build from here as the new Sherpa would seem to meet all your listed needs. Yay!
I'd need to know a bit more about the Sherpa wheels before I could make a recommendation. It appears the Sherpa has later spec components than the Commutour. If so, you'll need to keep wheel/cassette spacing in mind so you'll have compatibility between the cassette and derailleurs.
Unless you have a marked preference by tread or brand, I think I'd choose the newer/better condition tires of the two to keep, simply 'cos I'm uh, "careful" and would figure I'd get more use from them before having to buy replacements.
The handlebars will be a personal choice, but I'm guessing you'll end up swapping the Dawes flat 'bars and Ergon grips to the Sherpa. The Modolo Yuma has a variety of possible hand positions and
can be fitted with Ergon grips (See:
http://www.flickr.com/photos/cargonistas/4503908885/ ), but it is a butterfly 'bar, and so has the limitations common to that type: It is flexible, it tends to put the brakes pretty far in and back, and requires different positioning/stem length if not a different-length top tube.
Please note: The Thorn Sherpa brochure equates shorter frames with drop and butterfly handlebars and longer frames with comfort or straight handlebars. If you download the latest Sherpa brochure (
http://www.sjscycles.com/thornpdf/ThornSherpaBroHiRes.pdf ), there is a discussion of handlebars starting on page 3 and butterfly 'bars and the Yuma in particular on page 4. That might help make a decision, or you might need to swap stems in the trying.
If you think you'd like the Dawes 'bars from the Commutour, I'd sure try them on the Sherpa awhile before selling the Commutour. This woud give you a chance to see if you like the straight 'bars on the Sherpa -- which until now has been running the Yumas. You'll either know right away, or will need more time to make a decision. You could adjust the sell-on date for the Commutour accordingly.
I'm afraid I can't offer much more that would be useful till I see some photos, which are eagerly awaited! I hope you'll soon have the opportunity to try your wonderful new bike at length, and I'm sure the next person will await your Commutour with open arms.
Best,
Dan.