You can grow them in the ground, without training, along a 100 foot section of chain link fence, rock wall, concrete wall if you want.
As far as propagating a plant, what plant is easier to propagate then Dragonfruit.
Growing any edible you enjoy and having lots of it for free is ideal. I'm saying that at $6-$8 a pound there's plenty of other fruits I would buy before a Dragonfruit, taste and nutrition wise.
Also I agree about Red's or Purple's but I'd guess 75% of Dragonfruit that make it to market's around the world are white inside. Ive never seen a Red or Purple for sale anywhere before but I know So Cal has more going on with actual commercial farms of it and the Dragonfruit group.
The plants require a support, that takes effort and money. Then they need a raised box or pot with good soil, more effort and money. Then they need to be trained, more effort. Then polinated, and protected from animals. Not really that simple to grow. Throwing an avocado or orange tree in the ground is much simpler.
As far as taste goes, I would say they are pretty good eats if you get red or purples. Growing it and having lots of it for free would be ideal. Its a lot of work though so you pay for someone elses efforts.