Allright here it is my big Elinchrom ELB/Quadra unit versus the Broncolor 400L comparison review.  I have worked with both units quite a lot and wanted to make a comparison between the two. They both are great studio and out door units and both got their pro's en con's

Both units have quite the same specs and are really close to each other. For the comparison I will compare them one different features the have. 

Build quality  

Both are build for studio and outdoor use. Both units feel really well build. A big difference is that the Broncolor Siros 400L is a mono-head with a build in battery and the Elinchrom ELB/Quadra is a head and pack unit. With the Elinchrom ELB/Quadra the pack feel's like it is build like a tank, but the head is a little bit on the plasticky side. But the unit has no cooling or openings for cooling so it is kind a waterproof. Ideal when the weather is foggy or with light rainy, I would still use the unit. The Broncolor Siros 400 has a cooling fan which makes it less useable with bad weather of powder/sandy beach shoots. 

Weight 

Something really important for outdoor shoots is the weight. The Broncolor 400L head and battery weights 3.7 kilo's and the Elinchrom ELB/Quadra is around 2 kilos. An important thing to take in mind is that the Siros 400L has all the weight in the head, so on the end of you stand, with the weight of you modifier, it can be quite heavy. With Elinchrom ELB/Quadra you have the most of the weight in the pack which you can use as a counter weight or in a backpack. This makes it easier for moving around and rund and gun shoots. All though sometimes the cable can be a little bit too short. 

Battery Life

Both units should get around 400 full power shots on a full charged battery. But this is like with cars full usage test in the best possible conditions. So on slow charge, non use of the modeling light etc.  When used in reall life I get around 300/350 shots on half/quarter power. 

With the Elinchrom ELB/Quadra you can plug the unit in a power socket when available and shoot and charge at the same time. With the Broncolor Siros 400L you have to switch batteries. But the Siros 400L charge fast. You can charge a battery full in around one hour. 

Flash Speed

For action and dance photography flash speed is really important for freezing action. The Elinchrom ELB/Quadra has a fasted flash speed of 1/5700 with the action head on the B-port on full power. Which is around 140 watts/Second.

The Broncolor Siros400L is like the other Siros units build for speed. It has a fasted speed of 1/19'000 on 1 watts. On 50 it is on 1/7'000 and on 100 1/3'600. So with the Broncolor you can get better stopping power, but on a stop less power then the Elinchrom ELB/Quadra. 

High Sync

The new big thing in photography is High Sync. This is THE way to freeze action and combine natural light by giving you the option to shoot at Shutterspeeds like 1/4000 without loosing lots of flash power.

The Broncolor has a build in function for this with the RFS 2.2 trigger. Which is around €99,-. For the Elinchrom ELB/Quadra you have to buy a separate HS head and the HS trigger which adds around €650 to the price. 

I used both units with my Nikon D800 and D750 and I must say HS and Nikon with both brands is still not as good as it is working with Canon. I can get it working but have to keep adjusting the settings on the shutter speed for the best results. I also spoke with Broncolor and they say the HS works a lot better with the Siros 800L units. But I have not tested it with the Siros 800L. But with both Units I could get some great results!
 

Pricing

A basis Elinchrom ELB kit is around €2000,- for a main unit/battery, HS trigger, HS head and bag. A Broncolor Siros 400L with bag, battery and HS trigger is around €2250,-

Additional functions

Both units have additional functions like strobing, sequence mode, delay etc. The Elinchrom ELB/Quadra has a nice screen with which you can acces all the menu/unit options. Which make controlling on the unit very easy.

The Broncolor Siros 400L has a simple rotary dial on the back and a push, dial and click way for the basis options. For the more advanced option you can get an App which connects via the wifi and give you full control of the unit. Especially when working with multiple units this is really handy!

Which to buy

Now the hard question, which should you get? To be honest I can't answer this for you. I really like both units. I prefer the Quadra for more run and gun situations. The Broncolor Siros is slightly better for location where I can set everything up more or for fast portrait work. Then it is faster to set-up. I even putted the unit with attached 75 octa box on my back seat of my car, pull it out set it on a stand shoot and be gone 5 minutes later. with a great lit portrait. 

In the end I would likt to advice you to loan or rent both units, try them and see which one you prefer!