I rarely read this board, but just happened across your post. I can't compare the Concours to your 1800, but I just sold my 1500 interstate to pick up a 2008 Concours ABS, and can provide some comparison between those two.
I rode a GL 1800 for a couple of years, so have some experience with the GL 1800 platfrom.
So these remarks are about a 12 y/o Kawi compared to 20 y/o Honda. Both were ground-breaking when new.
The Connie is spec'd to weigh more than the Interstate, but unless it falls over, it feels just the opposite. I handles like a much smaller and lighter bike, and is much more nimble that the GL. The GL is ponderous in comparison and much harder to haul around corners.
The Connie has significantly more power, torque and responsiveness in the engine and transmission, which includes a 6th/overdrive. It cruises in low-3k region at 70mph. The engine with stock (ugly) exhaust is nearly silent, in contrast to the transmission whine of the GL. It pulls as hard if not much harder than the GL, but continues on right up to the 10k rpm redline.
The Connie has linked brakes, which many complain about, but I don't race and don't have any objection to them. I haven't had occasion to test the ABS, but like that it is there. The brakes are easy, responsive and powerful. The GL brake feel has more in common with HD.
Ergonomics on the Connie are typical sport-touring, with weight on your wrists. If you don't like that, you can add risers, pull-backs or very expensive adjustable Heli-bars to give you a more upright posture.
The upright & beg position of the GL had me wanting a driver backrest. Whole-body wind protection on the Connie is better than on the Interstate, and significantly better than on the naked or touring versions.
Like the GL, there are not many options for alternative footpegs, and highway pegs are difficult to install. Leg angle bend is about the same on both bikes.
I really like the electric windshield on the Connie, whereas the Interstate doesn't move. I cut down the stock Interstate shield to look better, it made highway speeds objectionably noisy. After adding a VStream windshield to the Connie, it is now the quietest of any bike I've ever owned. The interstate has included engine guards which work very well in protecting the entire bike. The Connie has none, and tip-overs can ruin every painted part ($$).
Unlike the attractive saddlebags on the GL, the Connie saddlebags are ugly but amazingly capable, useful and easy to open or remove. The GL has a 7 gal tank but 35 mpg gets you 200 miles and change. The Connie has a 5.8 gal tank but it lasts about the same distance.
I never thought I'd need it, but I really like the gear-indicator on the Connie. It has dual, easily-adjustable headlights, an integrated power outlet on the dash and a convenient glove box.
The Connie has tire pressure sensors, which is nicely reassuring. Many don't like the remote, keyless key-fob ignition, but I don't see why, and find it quite easy to use. It's no different than most modern cars.
The Connie has a center stand, whereas the Interstate does not, and rear wheel changes are a challenge. Connie suspension adjustments are easy to make, although many dis the factory units. They work fine for me. The Connie seat pops right off to get to tools, battery and fuses. The Interstate seat requires tools to remove.
The only serious negative I know of against the Connie is the valve check and adjustment procedure. On the GL, you can check valves in under an hour. Doing the same on the Connie will take a skilled owner an entire weekend or more, as all the bodywork has to be removed. Adjusting the valves will add a bit more time if you have the shims, or mail-order time if you don't. Thankfully, the valve check interval is 24k miles. The Connie has a timing chain; the GL has belts. The GL carbs can be inexpensively re-jetted; the Connie ECU can be sent out to be reprogrammed for $300-400.
Visually, I've always admired and enjoyed the great looks of the 50's styled GL Interstate. The Kawi is not the prettiest, but it is growing on me. The Connie can carry a passenger. The GL will carry a passenger in greater comfort and style.
In closing, the GL makes me feel older than I am and makes me think I could have taken the Oldsmobile; the Kawi makes me feel younger than I am, and makes me think I should have taken the longer road.
HTH, Gary
