Estimation method selection

Dear nmusers I am new to the field of pop pk. I am developing a Pop PK model of a compound by combining sparse PK data from 3 different mouse PK studies. I have following doubts/queries: 1. When we tried diff. estimation methods in nm 7.1 such as FO, FOCE or laplace. We got lowest OFV with laplace. Can we select the estimation method based on only OFV. We got the estimates in both FO and laplace but variability was reaching the boundary in case of FO. -Is it correct to make decision based on OFV across different models (one comp vs two comp). The diagnostic plots seem to be similar however variability was less with laplacian method as compared to FO. Which method of estimation would be most appropriate. - Is it correct to compare OFV across difeerent estimation methods (viz FO; FOCE; Laplace) - Is it correct to compare OFV across difeerent PK models (viz 1 comp; 2 comp etc) Inputs from experts are welcomed. Tausif Ahmed PhD Piramal Life Sciences Ltd, India