I've had the SC-500 since march 2002. Its been a great machine for me. Verry low maintenance. Just make sure it has the heater upgrade in it, if it doesnt you really should get it.
The only downside of it compared to other printers is its speed. It prints a 4'x8' per hour at 540dpi. Printing at 720 will take 2 hours to pull off a 4'x8'. For some shops this wouldnt be fast enough. For me it works out fine. Printing at 540 gives you great results and i can start it up and go work on something else and occasionnaly come back and pull on the print so it doesnt touch the floor. Smaller, fine detailed decals i will print at 720 but thats about it.
Maintenance is cheap on this printer as well since you only have one capping station and one pump. If you print allot (i do), a quick cleaning 1 or 2 times per week (around the heads, wiper and cap station) will assure you consistent results.
I havent had any issues with my printer eccept for normal wear and tear. I had the heads replaced in it after 4 1/2 years. For the price of it now i think its a great printer.