The '2' at the start of I205 means it is a belt way. Usually those are faster than the routes through the city (I5).
On Google Maps, I5/I84 is 6 miles longer than I206/I84. And with midday traffic their time estimate is 12 min longer.
If you did miss the I205 split, WA14 and WA500 are freeway quality cross overs.
There are many webcams in this area, viewable via WSDOT or Tripcheck (OR DOT), along with traffic flow maps.
Also the I205 bridge across the Columbia is newer, with an open concrete deck, and 4 lanes in each direction. I5 bridge is older (and due for replacement) with an overhead steel truss, and 3 lanes.