Investors haven't been thrilled with the latest operating results from Starbucks (SBUX -1.83%). Shares sat out of the 2023 rally and have trailed the S&P 500 so far this year, too.That performance could mean excellent returns from here if you don't already own the coffee titan's stock. Even if Starbucks is in your portfolio, you might want to add to your position. Here are a few good reasons why.1. Balanced growthStarbucks reported a robust 5% comparable-store sales increase for the fiscal Q1 period that ra ...