Totally not worth heading to YVR early. Its a pity, I am always wishing the CX or BA lounge had showers, instead the BA lounge has a shared bathroom that gets pretty dirty. The lounge also gets quite crowded and YVR is actually quite a nice airport to wander around. I wouldn't spend much time there at all except maybe a drink or two if that's what you fancy! The CX lounge is very soon after security and probably a 15 minute walk to the BA gate areas, the F section is typically very quiet but doesn't offer any exceptional amenities worth spending more than an hour waiting for the flight.