If you're looking for a "cheaper" shoe flash alternative then take a look at these two flashes from Godox. They not only fill the immediate needs for someone looking for a quality built, reasonably priced shoe flash, with many desirable features for both "On Camera" and "Off Camera" use but, they also offer great flexibility for future expansion options because they are wirelessly compatible with most of the Godox flash products using the Godox 433MHz or 2.4G wireless systems. http://www.godox.com/EN/Products.html
The TT600, priced at $75, is a Manual only flash while the TT685, priced at $120, is a TTL flash in both Nikon and Canon versions. Edit: You'll from time to time see cheaper prices than I mentioned here. Since I posted this thread, Godox has introduced their V860II lithium powered TTL Speedlites and Adorama has introduced their Flashpoint line of rebranded Godox products which includes the fore-mentioned Speedlites, some of which have been on sale for some very cheap prices.
These two shoe flash alternatives have the new Godox 2.4G proprietary Wireless radio system transceivers built in. That's right, both flashes have the ability to act as either Master or Slave flashes in the Godox 2.4G Wireless system. That means that both flashes, when used as Masters, can change wireless modes, flash power settings and trigger, respective of their specific flash features, any of the Godox 2.4G Wireless flashes with Slave capability: TT600, TT685, AD360II and AD600. They also have the ability to control flash power settings in the Manual only Godox strobes through the 2.4G XTR-16 receivers. The X1 2.4G transmitter can control both the TT600 and TT685 when they are set to Wireless Slaves. (see Flash Havoc write ups below).
The TT600 has the ability to control 5 Groups of Slaves (A,B,C,D,E) as well as it's own flash power separately (Group M) when used as a Master "On Camera" or "Off Camera" flash. You can choose between Manual and Multi modes. When in Multi Master mode the number of flashes and their frequency is set in the M Group for all Groups. An individual Group can also be turned "OFF". When used as a Slave flash it can be set to one of 5 Slave Groups (A,B,C,D,E).
The TT600 as a Master also works with the X1 receivers when a compatible TTL flash is used. Now when I say compatible, I do not just mean whether the flash is Canon or Nikon TTL compatible. I tested a Canon 600EX-RT, Phottix Mitros+ and Yongnuo YN600EX-RT, all Canon TTL compatible. The Canon and Phottix flashes worked just fine but the 3 Yongnuo flashes I tested would not fire. The TT600 could set a manual flash power but, the flash would not fire either when the shutter button was pressed nor when the test fire button was pressed on the TT600. This is not the first time that I have had issues with communication between Yongnuo and Godox flash products.
The TT685 does not have 5 Group capability yet (hopefully a firmware update will address this soon). The TTL TT685 flash has the ability to act as either Wireless Master or Slave flashes via the Godox 2.4G Wireless system, or via their respective Canon or Nikon Wireless Optical systems.
Both flashes use AA batteries and they have Optical S1 and S2 slave capability.
Flash Havoc write ups
TT600 http://flashhavoc.com …tt600-speedlite-released/
TT685 Canon http://flashhavoc.com …adio-speedlite-announced/
Nikon http://flashhavoc.com …-ttl-speedlight-released/
AD360II http://flashhavoc.com …ii-c-ttl-flash-announced/
AD600 http://flashhavoc.com …tro-ttl-strobe-announced/
X1 http://flashhavoc.com …gers-for-canon-announced/
XTR-16 receivers http://flashhavoc.com …itter-receivers-released/
When you look at the broad range of Godox products currently being offered, and when you stop and consider that they are all wirelessly compatible with each other, you have to be impressed. Their line of products are diverse yet it is easy to understand their individual mission roles and they are easy to use. Having such a diverse and fully integrated line of products to choose from, allows Godox users more creative options as well as the peace of mind to know, that as they expand their lighting system, that any new Godox flashes purchased will integrate right in with the Godox system they are already using.