Investors looking for stocks in the REIT and Equity Trust - Other sector might want to consider either Highwoods Properties (HIW) or Digital Realty Trust (DLR). But which of these two stocks presents investors with the better value opportunity right now? Let's take a closer look.We have found that the best way to discover great value opportunities is to pair a strong Zacks Rank with a great grade in the Value category of our Style Scores system. The Zacks Rank is a proven strategy that targets companies with positive earnings estimate revision trends, while our Style Scores work to grade companies based on specific traits.Both Highwoods Properties and Digital Realty Trust have a Zacks Rank of # 2 (Buy) right now. This system places an emphasis on companies that have seen positive earnings estimate revisions, so investors should feel comfortable knowing that these stocks have improving earnings outlooks. However, value investors will care about much more than just this.Value investors are also interested in a number of tried-and-true valuation metrics that help show when a company is undervalued at its current share price levels.Our Value category highlights undervalued companies by looking at a variety of key metrics, including the popular P/E ratio, as well as the P/S ratio, earnings yield, cash flow per share, and a variety of other fundamentals that have been used by value investors for years.HIW currently has a forward P/E ratio of 8.98, while DLR has a forward P/E of 25.51. We also note that HIW has a PEG ratio of 1.83. This popular figure is similar to the widely-used P/E ratio, but the PEG ratio also considers a company's expected EPS growth rate. DLR currently has a PEG ratio of 3.75.Another notable valuation metric for HIW is its P/B ratio of 1.46. The P/B ratio pits a stock's market value against its book value, which is defined as total assets minus total liabilities. For comparison, DLR has a P/B of 2.56.These are just a few of the metrics contributing to HIW's Value grade of B and DLR's Value grade of D.Both HIW and DLR are impressive stocks with solid earnings outlooks, but based on these valuation figures, we feel that HIW is the superior value option right now.Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Highwoods Properties, Inc. (HIW): Free Stock Analysis Report Digital Realty Trust, Inc. (DLR): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research