My home base is in Thailand, this last week I flew to Da Nang for a 46 day visit. Da Nang is a few degrees cooler so that's a nice break all its own. It's true about no fake smiles. It does seem at least 20% cheaper. Much wider roads, less traffic, similar pollution.
The beach walk in Da Nang is way bigger, better. It took awhile(last trip in
March) but I found several nice restaurants that serve italian, greek, uzbek, western, etc. and the service is excellent. It's great to go back and forth between Thailand and Vietnam as each one has it's benefits/drawbacks. I recommend Bali as well to get away from the pollution.