A lot has already been said but...

-Delta Medallion gets free WIFI inflight, thanks to new wifi provider. (Win for Delta)
-DL Skyclub offers abundant of locations and amenities, tho requires status and/or membership and DL flight (Win for Delta)
-AS Mileage Plan (AS offers more reasonable redemption value, whereas Delta Skypeso can be as much and even more than 4 times AS mileage to redeem) huge win for Alaska
-DL wins on Network and amazing IRROP assistance. (Delta win. Delta can often get you to final destination within 6 hours of original flight)
-AS care (Beancounters at AS care more about its flyers) Win for Alaska
-If nonstop flight is available, AS is often cheaper. (Win for AS)

Portland Specific
-PDX Lounge Both Delta and AS has comparable Lounge at PDX. (Draw)

Yes, while Delta is better in most perspective, AS tries hard to win your loyalty. What good is frequent flyer program when all desirable destinations/amenities redemption is out of reach for most members?

Jiburi

Having recently been dealing with BA's IT, I desperately miss DL's "terrible" IT, which in reality is significantly better. My AS IT experiences have been fine, perhaps not quite as good as AA or DL. (Most of things people tend to complain about on FT are edge cases, with the possible exception of DL's continued dumbification of their app. However BA regularly fails at basic tasks like logging me in and showing me my upcoming itineraries, or routine tasks like changing a ticket.)

Having gone free agent prior to the last round of DLevaluations, one thing I like about AS is it effectively offers a "premium economy" TCON service (marketed as domestic First) whereas both AA and DL offer nothing between flatbed J and extra legroom Y+. The JFK T7 lounge is also perfectly nice, perhaps not as grandiose as the new SkyClubs, but also I don't need to wait in line to get in.

If you’re a frequent AS flyer with many trips booked and a decent amount of changes (sdc, cabin upgrades) it’ll eventually start crashing from bad data and you’ll need to delete and reinstall. Haven’t had that happen with any other airline app.

Also the seat selection/checkin is quite buggy. I have been denied boarding before due to getting upgraded by the gate and it unchecked me in despite holding a boarding pass, and it wouldn’t let me recheck in on the app or online due to being too close to departure. They removed me from the flight as I was running from my late arriving connection. I had the option of letting them kick off a nonrev employee from a middle seat in the back but my upgraded F seat and original premium seat were gone.

Just this week I swapped seats last minute and somehow that kicked me off the upgrade waitlist. My name had already been on the board as number 1. A first class passenger no showed and a 75k member below me got the upgrade. The gate said they could see my status but I wasn’t on the list and maybe it was due to ineligible fare type (wasn’t on saver but that shouldn’t matter, was just a regular G fare booked directly using a travel certificate) but they weren’t able to override it and directed me to contact customer care.

These are just a few of the many annoying IT issues at AS. And that’s not even mentioning how buggy the upgrade processor is and all the silly tricks you have to do to stay on the list if you sdc, the games people play to bump you on the waitlist because AS doesn’t use original fare code for ordering, terrible new search engine, and the stale award inventory results.