it depends on how much you are planning to invest in it. Article writing is still manual labor and you are basically paid for your time and effort to create them. Micro niche site can bring you 'passive' income if you do it right. So if you want to earn money quickly, then go for article writing (and make sure you are good at it). If you are looking at long-term profit generation, further growth and are ready to invest your time and effort and make mistakes and learn a lot with the probability of making bigger money in the future, then go for micro niche website. It really depends on your effort and dedication.