In the end, the two things that might keep me with DL are that a) if I leave, I would need to drive 2-3 hours each way to MSP to use a different airline, and b) I can earn so many miles with DL (all the promos) and if I can plan my award trips wisely, I can get the low mileage level and find great value. My example with my SYD trip is a classic example.
i am in a slightly different situation as you.
i am on my own dime and the building block of my elite status is my 2 round-trips per year on HKG-east coast.
to be loyal to DL, it means i have to cough up for the expensive pricing.
fortunately, i manage to book a ticket on UA/KE this time for december/jan.
*A seem to have more rational pricing to hk. it may not be the cheapest all the time, but it is only slightly above the lowest. but DL is just giving a random price which i find very frustrating.
middle tier doesnt have lounge access (since i fly mostly on international route, so this is a big difference on DL vs *A). my airport is served by US/UA/CO/DL only. i have two choices when i go to hkg, and i am near where AC serves as well.
i have got okay value on redeeming my miles. booked 2 pvg-btv tickets for my friends. 4 hkg-nrt-gum ticket, and 4 hkg-nrt round trip. all on perksaver level. however, it is really frustrating to find those.
for now, i will switch my business to CO after i use up all my ECVs (let's hope i will earn more so that i can stay!)
i love NW, but i hate DL.