FO vs FOCE

Dear All, I know this is an old topic, too, but would like to see the statistics. When you have a dataset with about 10% of dense Phase II data (predose, 2, 4, 8, and 12 hrs post dose on day 1 and at steady state, twice-daily dose regimen) and about 90% of very sparse Phase III data (1-2 samples/patient), which method do you prefer: FO or FOCE? or FO for model development but FOCE for model refinement/finalization? If FOCE is not practical because of long run-time or numerical difficulties in converge, do you stop here or would you use FO? Thanks, Alan