DL gives some level of preference for upgrades to corporate travelers, so if your employer has a contract, this should help. Moreover, the discounts affect the price but not the fare class, so that should help a lot for upgrades since fare class is just below status tier in the factors that determine upgrade priority.

What is your status with DL? Unless you're a DM, you cannot expect free upgrades on elite heavy business routes, especially at consultant times. It might help to know more details about your travel patterns.