It depends on ELO and situation. Mid lane and in solo que she tends to build more assassin burst (stormrazors/duskblade builds) in top lane it depends a lot on match up.
For instance she was played in the LCK playoffs by Kiin (Afreeca v Gen G - formerly Samsung) and he built BotRK into RFC into IE into GA into Shiv and tabis for boots. That way she had reasonable sustained dps and the tank Jarvan could not enter her lane. Kiin even went W max second (which is pretty common for bot lane Quinn) for better sustained dps from the attack speed and movement speed buff.
Quinn is definitely unique in playstyle as an ADC and she leans more to assassin builds and playstyles but is actually quite versatile and in certain situations it is more optimal to play and build like a more traditional adc (generally other adcs do it better though).
The Stormrazor and Duskblade nerfs will hurt her, especially in mid lane but the AD growth nerf she is getting is going to be worse for top and ADC, that combined with the round of nerfs she just got to her passive damage and base armour which dumpstered her early jg she is going to be pretty bad in general for a bit.