I know and I know the situation there quite well. I am from germany and I was working there with Hensel for about 15 years. In the US I think Hensel is not really an option anymore.The OP is in Germany ... not the USA.
My assistants don't have to run from light to light. I usually use outdoor one or two lights and the assistants have the generator with them and the flash head on a boom. A lot faster and easier than setting up light stands outdoor.Working with assistants to adjust light levels is helpful, but not free. I would always prefer to adjust the lights from camera as opposed to having an assistant running from light to light ... especially lights in far rooms. That can be something of a circus act when working on a complex set ... including in concert with monos buried in a soft-box 12 feet in the air.
Yes, with monos that could be more difficult why I mentioned that the D1 are lighter. And they can be controlled.
The battery makers support their own brands. There is a list from Innovatronix from users but nothing about the Expert DI also use the D1s with the PCB Vagabond mini batteries ... but only as a supplement if I need to light a larger outdoor location. I do not know what battery may power a Hensel Expert D. Since it is digital control, I'd ask the battery maker before buying anything.
Like I said I have 1200Ws if I need it but also with a Canon I never needed it after I changed my light formers. Many Hensel user are using their beauty dish outdoor. It is a very nice dish in the studio but not very effective when it comes to a high light output. The Profoto gives you almost 1 f-stop more and the Elinchrom deep octa almost 2 f-stops with a very similar light. Two f-stops means instead of 1200Ws you can use 300Ws.1200 w/s from one head is useful when overpowering the sun mostly because most people do NOT have 1/1600 sync speed cameras ... and really helpful if the light is at a distance from the subject no matter what camera you use.
The new profoto zoom reflector is also more effective than the Hensel standard reflectors (I had almost all of them)
I agreeIn the end, I agree with Bill ... if you can afford Profoto, including any future generators and accessories, then go for it ... the modifier mount alone is worth it. If the investment is too much, then Hensel is a fine German made product that produces an excellent and consistent quality of light, and offers some very affordable and innovative modifiers ... some of which are not available elsewhere.