Well...I just got back from west Texas...my old stomping grounds.
I used to do top end runs in every car....bike...and HORSE I ever owned out there. The roads are flat, straight, and no traffic.
So
Sunday afternoon me and a buddy from Houston on his '07 Busa took 67 south of Marfa. On a stretch where the road was flat and straight for well over a mile we rolled 'em up to see what they'd do. We could see about 2 miles down the road where a rise terminated in the horizon.
Sufficed to say I am utterly please with this C14.

It is one bad bagger. I dropped the big Kaw into 4th and pinned the throttle. About 135 - 140 I shifted into 5th and kept it pinned. The Concours is amazing how rapido it nails 160 mph. At that speed it was still pulling pretty hard up to 165 mph (indicated on the OEM speedo). From there it took a little longer to climb on up to 170 indicated. Actually it was a hair under 170 indicated. I had my Zumo to record GPS max speed. It may have gone a little more but probably not much. I was running out of road very quickly at that speed. Here's the image I captured off the Zumo:
After the bike seemed to level off on top speed I held it there for 3 or 4 seconds to make sure the GPS calculated an accurate speed. I t appears my OEM is about 7 mph fast to the Zumo. Not surprising since Jap speedos are notoriously "optimistic". But the fact this bagger will bust 160 mph is impressive.

It even impressed my buddy on the Busa. he was surprised I could hang that long with him.
However....the Haybusa is unbelievable. He let me take the lead so I was out front by a couple bike lengths. When the Connie hit 160 the Busa started slowly walking away. When I was indicating 165 it was obvious the rate of acceleration of the C14 was beggining to wain because the Big Suzuki really started pulling away. I think his true speed was approaching 175 when mine was 163.

And he said his Hay Bus was still gaining speed when he pulled the plug because we were fast approaching a rise in the road.
My bike has had a few mods:
AreaP Dual exhausts with a ZX14 header - no cats at all
BMC air filter
Flies out
PC3 USB with custom map
My bike has been dyno'd at 144+ RWHP and 96+ Ft-lbs torque
Also I had the hard bags on but they were empty. We left all our gear at the room. The bike was very stable at that speed even with the bags on. So who knows...with the hard bags off ya might squeek a little more out of it...probably not much.
Also the road was straight and flat....but it did have a very slight downward pitch. Zumo indicated we dropped about 20-30 feet in a mile...so it was very slightly downhill.
What is it like? Freaky. Things are going by so fast it's all you can do to focus on the road ahead. It's takes alot of concentration to simply glance at the cluster to read your speed. When I pulled the plug (throttle off) it felt like I must have coasted a quarter mile before I touched the brake. Fun? Yes...Un-nerving? certainly. DO it again? Not likely. I've satisfied my curiosity.
Honestly I don't know how some crazy bastidz ride that speed for mile after mile. A mile or two of that and I'm done.