Similac Alimentum

Does anyone have any experience with this formula? We just started my 2 month old on it (switched from the breast due to protein intolerance) about 4 days ago. Her poops look better but she is still very fussy and I read the ready to feed version may be easier for some babies to digest. But we just bought like 9 cans of the powder version so I don't know how long I should give that a chance before trying the liquid. I am so ready to have a happy baby!