best mid-price flash for Sony A850
I've had a Sony A850 for almost three years, and I've used the basic low-power Sony flash, the HVL-F20AM. It's an adequate basic flash, but I'm wanting something with more power. I use flash mainly on camera in bounce mode indoors, and especially where ceiling are high or I'm doing groups, the F20 is under powered. The Sony F43 would be ideal, but at $348 is a bit more than I want to pay. I've narrowed my search to about 4 flashes:
1. Sigma Ef610 DG standard at around $135
2. Nissan DI622 at $230
3. Metz 44 AF-1 at $200
4. Sunpak PZ42X at $139
From reading around the Internet, these seem to have roughly equal built quality. The Sigma has the most power by far at flash guide 61, the Nissan and Metz are both around 44, while the Sunpak is 34. I'm unlikely to do anything with masters and slaves or anything complicated any time soon, so I'd probably go for the stripped down Sigma at $135 rather than the one which supports more advanced flash work. The Nissan seems to be well reviewed and looks appealing and does seem to support all the advanced stuff. It's probably the lead contender at this point, although it's the most expensive of the bunch. I've seen claims that it is superior to the Nikon flash which costs twice as much. The Sigma clearly seems the biggest bang for the buck, although there are complains about how complicated it can be to use.
Does anyone have any suggestions or comments to help me make my choice? Any critical features supported by a particular model. Any advice would be appreciated.