I've still never ridden a bike with a sidecar. Still tend to think they are cool looking rigs. This one even more than most. 
twolane,
Thanks for the kind words... I don't know if you saw the Ebay add I put up that greg moved to third party for sale (yellow 09)
It's more counterbalance than anything else... not being able to lean the bike into a turn is the most unusual sensation.
Right turnpike (onramps) for freeways are probably the hardest.
Reading several guides, a lot of people put ballast in them to help. I'm not a little guy so I don't add ballast, you just have to remember that there is a physical limitation to the speed at which you can enter a corner before it will try to toss you off...
Regardless of how much counterbalance you put over the car.
The onramp speed limit is about the limit.
Both the Hannigan and the Motorvation have Electronic Camber control, meaning you can raise and lower the car height slightly to counter the crown of the road, on ramps, etc to help make turns a little easier.. makes a HUGE difference. takes a little getting used to as its another gadget to mess with while you're riding. I noted the Motorvation hack even has independent brakes... talk about a bunch of stuff going on.
I'd love to try to ride the yellow one fully loaded, wife on the back, dog in the hack and a trailer full of gear just to see how it feels. must be one hell of an adventure.
The previous owner either loved it, or hated it.
I've put almost 4k on mine riding it daily since April until the stator died. (It sucks being on an island waiting for parts.) That tells you what I think about riding a hack despite its challenges...
I dont have to put my feet down in traffic and I can carry as much beer as I need for parties...! Costco trips are a breeze now!