Definitely complain, and I'd ask for miles for compensation. 50 minutes is unacceptable.

30 minutes after the seatbelt sign goes off I start complaining to Delta on Twitter, and Delta Assist usually responds. They can't do anything about it immediately, but hopefully they're identifying problem airports. For me it's usually JFK.

If Alaska can guarantee bags in, I think, 20 minutes then Delta should be able to do the same.

As a side note, Delta's baggage handlers in PDX rock, and I tell Delta that too on Twitter. Bags are almost always out in under 20 minutes, and priority bags are always first.