You can get 1 sample to try. Best is stick to one fm. If keep changing fm. Baby will tend to get colic and discomfort. Or reject milk Unless baby has shown not suitable to 1st fm.
Any particular reason why you want to change the brand now? Both are good.. But price wise, nature one is so much better.
No particular reason , just see if nature one the nutrients got better than similac anot. Ya the price wise nature one is must must more saver. Have you try nature one?
joyjoy