It's a nightmare in heavy traffic, coming from the east, everyone needs to go north through the tunnel, north of Gullbergsmotet, and there's a single lane, and noone plans their route properly, so instead of a long and orderly queue you get 3 lanes trying to merge into it at the very last second!
I've done it once, and I'm never doing it again, I drive 15km extra around Gothenburg and come in from the northeast instead, it's faster..