1st prize
Clear winner: Metz MB 44 and Nissin Di622, both cost less than half of the Sony device. The Nissin you get some already under 100 euros; It must be careful, however, something one, because is only about the German importer Hapa eigeführte devices of this 5-year warranty and free firmware updates).
2. Flash output
Tie: The Sony is a guide number is lower (43 instead of 44), but that makes the carbon non-greasy.
3. Size
Tie: The Nissin 622 is in particular in the lower part a bit more slender than the two competitors. Otherwise, take your height and weight slightly.
4. Operation
Sony HVL-F43A> Nissin Di622> Metz MB 44. Sony is the only one LCD display and a lot more dedicated buttons; Operation is intuitive with Nissin mE than in Metz, particularly liked the easy setting manual exposure via rocker switch and indicator -1.5 to +15 EV on the device.
5. Functions
Sony HVL-F43A> Nissin Di622 = Metz MB 44: The Sony may the only HSS and stroboscopic flashes. In addition, the flash head is more widely rotation (good if you hold the camera vertically while flashing the ceiling and use the diffuser plate will). Otherwise, the three devices do not take much. In particular, as Metz Nissin are also Suitable for wireless (WL) flashes.
6. Scope of delivery
Sony HVL-F43A> Nissin Di622> Metz MB 44: the Metz is unfortunately not supplied stand, in the two other already
7. Firmware Updates
Sony HVL-F43A> Metz MB 44> Nissin Di622: The Sony does not need a firmware update, the Metz can make via USB even in Nissin you have to send in the flash (is then made however for free)
8. Tests
At the big chip Photo / Video Flash Nissin test of the Sony came in 11th place, 12th place and Metz at No. 14th
9. Conclusion
I bought the Nissin Di622. The advantages of the Sony flash rewarded my opinion not the higher price.
Metz Nissin and are very close together. For me, better equipment was (feet for external flashes supplied) and usability (see above) shall be decisive; Firmware updates I do not need, because even the Nissin works perfectly with my Sony A57.
The Nissin Di622 sits incidentally bombproof and jolt-free on the A57 (in other lightning is sometimes reported to wiggle, but that can also be series variations).
This is of course my subjective opinion and everyone is free to take a different view.