I am looking to let Sparkletts water go, they have been very unreliable in their delivery the last year/year and half and I have been too forgiving. The water tastes great, but the delivery service never shows up when they say they will. Does anyone have a reverse osmosis water system you would recommend? Is it hard to install? I don't want it to take up much room in the sink cabinet. Plus, I would "like" to have instant heat if possible, which is something I will miss with the sparkletts dispenser.