This week, Cboe Vest launches the Cboe Vest S&P 500® Dividend Aristocrats Target Income ETF, a fund that combines the dividend aristocrat universe with a covered call option income strategy to deliver high yields and the possibility of capital gains.How it works is that the index provider starts by purchasing an equally weighted portfolio comprising the optionable stocks in the S&P 500 Dividend Aristocrats Index, and writing exchange-traded covered call options for a partial amount on each stock. In other words, the option strategy is designed to provide a yield boost to the portfolio, but it's not necessarily going to maximize yield by placing a full covered call overlay.One of the drawbacks of a fund that uses a full covered call strategy is that, while total dividend yields can surpass 10%, they usually lag the broader market because the winning stocks in the portfolio are getting called away at a price lower than the current market price. On the flip side, covered call ETFs can outperform during sideways or declining markets because the options written expire out-of-the-money with the fund pocketing the premium. I like the notion of a partially covered call strategy because it can provide the best of both worlds - higher yields with fewer winners being called away.Part of the objective of KNG is to deliver a dividend yield that is 3% higher than that of the S&P 500.With the S&P 500 yielding around 2% currently, that would put KNG's target yield at around 5%, with the ability to rise and fall depending on changes in the market.While dividend seekers will find the yield appealing, covered call ETFs have a mixed history of success. With the market having risen in a straight line up over the past couple of years, covered call ETFs have trailed the S&P 500 badly.Over the past year, covered call ETFs have trailed their underlying benchmarks by 8-10%, despite the higher yields. They've still trailed in 2018 in a choppier environment that should work a little more in their favor. In short, KNG has a nice yield, but over the long-term, these funds tend to be underperformers.What do you think? Is the 5% target yield on this fund appealing or would you be avoiding this strategy? Comment down below with your thoughts! For more ideas like these, be sure to join the ETF Focus group here on WhoTrades.