Understanding the bull and bear arguments can help investors make a decision.Just like that first cup of coffee in the morning, Starbucks (SBUX 3.11%) received a jolt of energy when it announced a surprise leadership change less than two weeks ago. Laxman Narasimhan, who was the CEO for less than two years, is being replaced by someone many view as a superstar in the restaurant industry.But what might look like a positive development doesn't mask the fact that this top coffee stock trades 26% off its peak p ...