I've had one for over a year. Family (4 yo and 2 yo boys) loves it. I've added numerous upgrades and will note the ones I consider "mandatory" for maximum enjoyment.

1) Tires (mandatory) > Schwalbe Big Apples (2.15"). Please note, these take some modification of the fender mounts to fit. Mostly using p-clamps for the rears.

2) Handlebar (mandatory) > I upgraded to Wald 896 cruisers, any wider more swept handlebar works (note, 2011 handles seem to be more swept)

3) Front mounted carrying capability > I opted for a wald basket w/ bag... currently lusting after the new Madsen from basket.

4) Pedals > MKS Lambda / Grip Kings... I just like these... rather than the stock pedals. Pedalites might be a good option...

5) Saddle (future) > likely a VO city sprung saddle

6) Handelbar Water Bottle Cage > the existing cage mounts on the down tube are basically useless as there's not really space between the tubes... trying to find a decent side entry water bottle cage that works...

7) Lights... still deciding how best to do this... with the new front rack, lights and water bottle becomes easy... well, rear light is a challenge... the totcycle.com guys have a sweet rear light. Thinking of swapping the rear fender reflector for a PDW fenderbot... or finding a way to put on the new cateye reflex auto...

I have to say, the 2011 Madsen is highly desirable. VERY nice upgrades they've put into place.