Hey Mike,
Pretty much a crapshoot if you're driving solo. 405 will bog a bit in Renton, Bellevue, Bothell, Lynnwood...... but 5 usually bogs by Boeing, Downtown (lose a lane, unless you go express lanes), North Seattle, then the previously mentioned Lynnwood/Everett traffic. My gut says to take 5 and the Express lanes. Once you hit Tacoma, pay attention to traffic reports. Watch for words like Boeing, Tully Roaster/Brewery - I5 traffic, or 'S' curves, Kennydale, 520, canyon Park for 405 traffic.
Hope it all goes well.......
David
