Similac vs Kirkland signature

I'm currently using Similac partially broken down for my little one, I'm thinking of switching to Kirkland signature infant formula - sensitivity but it's for babies sensitive to lactose and I'm pretty sure my baby doesn't have a problem with that? Can I still use it or would the Kirkland omega+ be better? I'm just looking for something that's similar to what I'm currently using but is cheaper. :)