Yonguo has a reputation for variable quality. Some models don't seem very reliable, some are fine. I don't know which are which. (Or even if they've remedied the problem.)
I can say that for far less money than Nikon SB-700, both Sigma and Nissin offer nice units, namely the Sigma EF-610 DG (not the EF-610 DG Super) and the Nissin Di-466. Both about $150 and both have both have heads that rotate in two axes. Neither can act as either remote or commander in CLS.
I have a moderate amount of experience with Sigma flashes (including one that I own) and they have been reliable and accurate at metering. Perhaps not *quite* as accurate as my Nikon flashes (of which I have six), but call it 97 vs 99.
The other alternative, also suggested above, is a used SB-600. Half of my Nikon units are SB-600's, and truthfully I use one of them significantly more often than I use my SB-900. The 900 is much bigger and despite being my only CLS commander, having more power and more flexibility, most of the time I just need some bounce flash. So I reach into the bag and out comes one of the SB-600 and I'm usually set for the day. (The Sigma that I own is an EM-140 macro unit, so it doesn't compete for most "regular" photography.)
_____ Brian... a bicoastal Nikonian and Team Member
My gallery is online. Comments and critique welcomed any time!