This article is based mostly on the agile SDLC model. I prefer the waterfall for simple projects(less than 1 month) although I worked on a 2 year project using the waterfall model which went super smooth, 1 iteration. It was super well planned and had lots of experienced minds involved. I worked on a 10 months agile project which we kept going to back to design and analysis phase several times then got stuck on testing for longer than needed.

I don’t prefer waterfall. Projects using waterfall tend to try to stick to the plan till the end even when changes are needed, they take long, require experience and good research. Agile you can discover as you go and change accordingly which can be stressful.