A few months ago I bought a harp trolley from the Harp Shoppe in Loveland, CO and I love it. It’s made of aluminum that’s strong yet lightweight and also easily breaks down for storage. It has a slightly wider wheel base than my old Salvi cart which gives it greater lateral stability – also wide enough that the wheels don’t rub on the harp case. Big pneumatic tires with grippy tread give a smooth stable ride over gravel, grass, stairs, curbs, etc.
One of the best things about it is the placement of the two straps: One is around the middle of the harp and then another over the top of the neck. The harp is held very securely on the cart so if somebody tries to “help” you up the stairs they can’t lift the harp off the cart. I use it for both my concert grand Camac Atlantide and a semi-grand Wurlitzer. The shelf is big enough and straps adjustable enough that it’s also useful for hauling an amp.
At $195 it costs less than many other carts and because it can break down into a small space shipping costs less.
The only negative I can think of is that when I first unpacked it there was a strong rubbery smell from the tires and the cushy neoprene that covers the handle portion but that wore off in a day and is no longer an issue.
I can’t say enough good things about it, I give it two thumbs up.
Information is available here:
http://www.theharpshoppe.com/accessories.html