I just got one of these flashguns and they are awesome! There is no TTL mode so it's fully manual but its a great way to learn how to use flash.
The unit feels just as well made as either of my Nikon speedlights and to put it into perspective you could buy four of these for the price of one Nikon SB700 or six for the price of a single SB 910.
It also has a slave mode so other flashes can trigger it. For users of Nikon's CLS system, the slave mode can be set to ignore the pre flash. You can use a PC cord if you prefer. An external battery pack can also be added.
Click on the link below to buy from the same supplier I did, they are located in the UK so it will be a bit faster. Amazon has several suppliers but some are overseas and delivery is slower.