The difference between glyburide and glipizide?

Both medications are common sulfonylureas use to treat type II diabetes. However, glipizide has a shorter half-life compared to glyburide (12 hours versus 22 hours). And glipizide has a lower incidence of hypoglycemia. Although the pharmaceutical companies want us to prescribe their newer oral agents (which are not part of the ADA guidelines), sulfonylureas like glipizide are considered "well validated" and "Tier I" medications for the treatment of type II diabetes (after metformin).