There are essentially 2 things to consider when looking at these plans. 1) what is the cost (expense ratio) and 2) what is the composition over time?
The expense ratio, as I'd expect from Vanguard, is
very low at 0.18%. Their target date funds are just bundles of their index funds, as that page shows. Over time they will shift the allocation in the target date fund to have more of the bond indexes and less of the stock indexes, as retirement approaches. This is the standard approach to diversification as retirement nears and is one you should follow, whether you go with their target date funds or with individual funds.
What I suggest you do is look at the way they plan to change the allocations over time and see if you are comfortable with their level of risk. Which is to say, what the mix of stocks and bonds are 10, 20, 30 years from now. (That should be in the fund plan or prospectus, on the site I linked). I find target date funds tend to be a bit conservative in general (without having looked at this one in particular), but if you are comfortable with that, target date funds are a good "set it and forget it" way to save for retirement. They'll do the rebalancing for you, both over the year and as time passes. And by going with Vanguard, you are going with the best / lowest cost company in the industry.