This machine really performs well with no spotty glass. this machine does a spot free cleaning do your research and you will find that Unger uses approximately 40% more resin than Filtered machines. How much did it cost the last time you paid for filters to find that you still had spotty glass? I would recommend metal fittings over the plastic ones that come with this machine. Get the cart you will not be disappointed It has a Digital TDS meter it has solid rubber tires that will not go flat, its built solid I attached a hose real on the back of the machine.it is not to heavy and can be removed from the cart so its portable & easy to change the resin bags. the price is reasonable for what you get Unger makes solid products. I will be buying another machine from Unger.