Is app switching (multitasking) better in new lumias and w10?

[Satyam Choudhary]

I'm using 620 and switching from one app to another take so much time(thats the only bad glich in windows os). May be its coz of 512ram and slow proceser* but in new phones is this prob minimized? Like in 640,730? Or after updated to w10 on 640,730? (Or any other phones). Specially WhatsApp, is it still [loading.....] in w10?