My order of work would be: verify the 125 m² basis, establish occupancy and any lease details, obtain the service-charge and building information, identify parking/outdoor rights, then revisit the completed comparable. Only after that would I pay much attention to a fine-grained condition...
The comment about management and one bad year suggests two questions are being mixed together: what the condo is worth and whether it works as an investment. Keep separate calculations. One should compare the property with alternatives; the other should include service charges, management...