I think VWO is a safe choice if what you want is passive indexing of emerging markets. Yes, it's very volatile but that's what you get in emerging markets. Perhaps there are a few slightly better ETFs but I doubt there's anything that's significantly better.
I use VWO for custom asset allocation. Most funds and ETFs that target non-US markets invest very little in emerging markets (VXUS and VEU both have about 15%, for example), and I prefer to have a bigger slice. I also own some EWX to fine tune my portfolio and increase the allocation to mid and small cap stocks in emerging markets (VWO has only about 12% mid and small cap combined).
Disclaimer: I'm not aware of any consensus opinion on what's the optimal allocation to emerging markets, except that it should be greater than zero. Increasing the allocation compared to well-established funds like the Vanguard Total International Stock Index may or may not be a good idea. It's just my personal opinion that it is if you're investing for the long-term.
The most commonly accepted advice for buy and hold investors (it seems that's what you want to do with your emerging markets investments) is not to delay your purchase hoping for better market conditions. Since your attempt at market timing suggests the same (buy now), you might as well go with it. (I cannot comment on whether you'd be better off waiting, and I don't think anyone can. Statistically you tend to be better off not waiting.)