Both are countertop RO systems. The Pro mainly earns its premium through a richer dispensing experience rather than a radically different purification concept.
Choose R9 for the better value if hot and ambient water cover your needs. Choose R9 Pro if chilled dispensing and extra appliance features are worth roughly €100 more.
Both use reverse osmosis, UV treatment and remineralization-oriented positioning with countertop reservoir operation.
The R9 Pro adds cold-water functionality and a more premium dispensing setup. That matters in warm climates or offices where chilled water replaces bottled water.