Energy deserves the same treatment. The studio’s 590 sq ft footprint suggests lower personal consumption, but building-wide systems and charges may blur that advantage. With the duplex, look at each unit’s equipment, insulation and utility metering. Ask for actual historical utility information...
I’d go further: days-on-market may be the wrong feature to value most if listings can disappear and return. Without a visible listing history, a low number could describe the current advertisement rather than the condo’s total time for sale.