How difficult is 27' motorhome to drive in city traffic?

Get around vehicle once at my destination - sure. Using a coach is doable but there are more down checks that up. Each time you want to head out you'll need to repack the interior of the coach for travel and break camp. On the road don't forget you'll be traveling in something getting less than 10 miles to the gallon to get there. Once you arrive parking can be difficult.

City driving isn't too difficult but you will need to preplan your route with consideration to you height, weight length and width limitations. Know your turns and lane requirements well in advance.

Don't write off towing a small car even before you start your adventure. Depending on your travel and sight seeing plans it might be a better option.

I drove our 27 Pursuit through NYC during rush hour. Jeep CJ toad.
It's not much longer than a Ford Excursion.

I consider a 27' class A much easier to drive than your Excursion TT combo.
You have to be a bit more concerned with height but otherwise you will find it much easier than what you have

don't try to use one of the down town parking lots in New Orleans.
bumpy

What city? Don't try it in Boston!

I'm just a typical guy who never drove truck or towed anything. When I purchased my 27' Class C Motorhome in 2012 I was naturally intimidated by the whole process. It has turned out very well - easy to drive and park. And I have driven it through New York City! The compromise for me is I sleep above the cab (no walk around bed). I am a big fan of this size unit. Easy to up and go. I do tow and that has turned out to be easier than expected as well. You learn to be aware of your surroundings and "always look ahead" before you pull in anywhere. Once I disconnect the tow car, I can park almost anywhere.
The hard part is finding an interior configuration that meets my needs. My floorplan has 2 full size couches and a full dinette and full bath area. But no walk around. Most folks seem to want a "made up bed", well we have 2 but not a traditional Queen. The Queen above the cab and we have laid an extra long Twin Size mattress topper on one of the 2 couches and have a bed that doubles as a day bed during the day. Hope this helps!
Todd
'99 Lazy Daze Rear Bath Model
'02 Honda CRV

(To your specific question, my unit has a window in the back and that makes it infinitely easier to drive in my opinion.