I'm too lazy and too much of a neat freak to go the RO/DI way, until I build my next place that is.
The RO/DI line can go through walls. Rallard professionally installed my previous RO/DI neatly under the sink. He installed one line for the RO drinking faucet & one line for direct topoff to the sump using a Kent Float Valve. The Penguin machine in my town is check once or twice a week.