1) Bigger units usually mean more people per unit, so density might not be that different overall between Artessa and Quinn. Especially so if Artessa units all come with multiple car park, means more likely to have family own stay and landlords will rent units out by room.

2) This one ah, honestly high units will need to get soundproofing anyway, because anything above level 15 that isn't protected by trees/buildings will be able to hear traffic/transport from 1km radius away. Sound travels VERY far. Both condos will be affected by noise since both are surrounded by busy roads in highly populated areas and are near to the LRT track (runs along Jln Mohd Yatim Yahya which Artessa is next to)

(pic below stolen from Sunway Avila thread)