Computed column vs trigger -- Performance question.

Hello, 

I have a customer table with the full information, about 20 columns of data, and I need to get a numeric value according to complex combination of 10 of those columns using CASE. 

I would like to know what is the best option get a decent performance behavior. 

1. Create a complex trigger on insert/update, to re-calculate this numeric value. 

2. Create a complex computed column 

Please note that this table have arround 300k rows and it is drop and created again with fresh/updated information every week. 

Actually the importing process with the trigger took around 5 hours. so maybe the best option is to import data without trigger or computed column and do a complex update table after everything is imported. 

Please advice. 

Gilberto H.