I also have the party star setup and it is wonderful.
Mine also leaked a little one time out of 6 tries, where the nossle goes in the bung.
Its nice because unlike the ones that lie on thier side, you can carefully carry this around and fill people up as you visit with them.
The equipment is top notch, the only problem I have is the plastic lever you pull down to dispense sometimes pops off but you just put it back on.
I sometimes get to much CO2 and the beer comes out foamy, but I think I have fixed that by making sure that its at the lowest setting when I put in my cartridge.
I also heard horror stories about the cans being weaking and deforming. I havent had any problems with that. If you prime to much, which I did once, the part of the bung pops right out or the entire bung does. Not enough pressure will build up to damage the container.
You can also use coors light/molson and other 5 litre kegs if you dont purchase enough with the tap.