I have never owned a quality reel before and would like the opinions between these two. I would be using it primarily to fish for salmon in AK.

Don't fish for salmon but I use the calcutta 400b for muskies. Excellent reels. No complaints

Can't go wrong with either of them.

Never used the Diawa but my Calcutta is a salmon stomping machine. I've had Garcias, Penns, older Diawas and Quantums and none of them can hold a candle to the Calcutta IMO. I'm going to buy one of the little ones for bass fishing when I get back down south and use my 400 for a trolling/catfish reel.

I really appreciate the feedback. Certainly seems like the Calcutta is a bit more popular.

I once asked a reel repair friend of mine which brand of reels he sees the fewest of and he quickly said Shimano by a large margin.

At the time I was using Garcias, Diawas and Quantums so I started to use Shimanos and have never regretted it! I have yet to have one fail me. I can't say the same thing to the others....

Based on Brand durability and parts availability I would choose Shimano. I have been repairing rods and reels for over ten years.

Quantum isn't is the same class....

Are you fishing these in the salt or for casting in the rivers?
I purchased a couple of new Daiwa Saltist 20HA last summer for salmon fishing down here in Washington in the straits of Juan de Fuca. I use them mainly for trolling and I really love them. Very smooth. Fast retrieve. Drags are awesome.

Most of the time would be in the rivers, but when I am asked, I try not to miss a time to go out on the saltwater in my friends boat. I would say 80% + of the time would be freshwater.