Figured I'd summarize a conversation had in real life with a photographer just starting to dabble in strobes. Like most photographers that do a lot of outdoor work with no additional light beyond what god provides he has one speed light and needed some guidance on what's next. Good question but as usual it depends on what conditions you're optimizing for.
I've gushed about my love for the Profoto B2 in a few posts so you know I vastly prefer it over any speedlight solution for most if not all of my own uses. I think it or something very similar in characteristics would fit the bill for a lot of other people as well.
Considerations vs. Speedlights
First off speedlights can be cheap but realistically if you're buying Nik/Can/Fuji/Etc system speedlights, especially the newer radio controlled ones, they really cannot be considered a cheap solution. OTOH if you are going with the one of the plethora of Chinese solutions that are perfectly workable they could be.
In terms of portability and size speedlights can be more compact but only if you can jamb one or two of them in a bag you already carry and don't need a lot of flashes or great recycle time or a lot of power, or a bunch of adaptor stuff to mount modifiers. If you need the power it's going to take at least 2 maybe 3 speedlights to equal one Profoto B2 head. If all of a sudden you find yourself buying "extras" to make speedlights work for your conditions (battery packs, multiple mounting solutions for modifiers, etc) the size/weight advantage disappears real quick and brings with it a ton of complexity, fiddly-ness, and potential reliability issues.
The Profoto B2 on the other hand is absolutely reliable, can now do TTL (if you want/need) with Nik/Can/Oly/Fuji/Sony — pretty much everything. Has plenty of power and plenty of flashes on a single battery charge (if you need more batteries are cheap and actually smaller than speedlight battery packs or a ton of AA's). It's also not at all fiddly nor does it require anything to mount all sorts of modifiers. Oh yeah, it has a decent modeling light as well. In terms of grip and stands lets say whatever you need you need and will be the same with speedlights or the B2 minus the adaptors required for mounting with the speedlights.
That's not the full story though. If you have a speedlight or even if you don't that might seem like a good place to start right? Ummm, maybe but only if that's where you plan to end up. What if you need two lights… or eight… or a lot more power&hellip, or??? Then things get a bit more complicated. Sure you can use your speedlights with other stuff but not really. You can't in a seamless integrated, get out of my way kind of sense.
With the Profoto B2 it integrates perfectly with every other light I have. Every one has a built-in radio (the air system from Profoto is probably my overall favorite, it's quite good). I use the B2 all the time with my big lights (D1's D2's and generator/heads). Completely seamless and 250 w/s seconds is perfectly fine and usually way more than enough for accent lights, grids, and gels when paired with much more powerful lights powering large modifiers. The fact that I can use a lot of my modifiers with any of my lights sans adaptors is awesome. Did I mention I hate fiddly-ness.
Design. In one word design and U/I with all of the Profoto products across the board is almost identical and very photographer focused. Intuitive knobs and buttons, extremely quick up/down on/off modeling light on/off, etc, etc. All from very very easy to read in any conditions LARGE bright comfortable displays both on the remote or the light or the pack. All the same, all one of the best user designs in terms of real world "get on with it" use. Not at all the same as the shitty speed light displays/controls etc, let along dealing with 42 different remotes, user interfaces, adaptors, wires, etc.
What Can't The B2 Do?
Well, compared to speedlights not a lot beyond it's cumbersome to mount on your camera (but can be done and it's not really heavier than a speedlight). What it can't do is more focused on what it can't do vs say a B1 or a D2 or a Pro-head. Namely what can't it do compared to other Profoto lights.
- Don't plan on mounting your RFi modifiers like octa boxes etc on it. It might be sturdy enough even for the big ones, maybe but more importantly the front of it is not at all long enough to actually poke through the RFi speedrings into the actual modifier/box. It's just too short so expect less than even output, especially on the larger mods. I'd also expect some loss of effective power.
- The same goes for any of the gorgeous Profoto hard modifiers designed to be zoomed back and forth for differing effects. See the reason above. Sure you can do it but it's got only one effect and that's with a flat face buried way back before the actual reflector surface even starts. Not good.
Honestly that's not a big deal to me since I regularly use diffusion gel and large umbrellas as well as your typical boxes and like I said when combined with other lights from the system I usually use open, gridded, and/or gelled.
What about when traveling. Well I typically take two modifiers; The OCF beauty dish and one of two or three large umbrellas with a diffusion cover. If you start talking big boxes and larger hard reflectors you aren't packing light/compact any more are you? Especially when you consider the grip/stands for that other stuff. While not a perfect solution I find the OCF modifiers (Octa/strip/box/beauty dish) a great option. They are FAR lighter (especially the speedring) than their RFi equals. Probably a bit less durable as well but that's fine they are also very inexpensive (around $100 each). The OCF speedrings are very packable and most likely very durable so no worry there.
As for the hard modifiers (that I love) honestly they are all very limited if using a flat-front Profoto light. More on that another day. What is cool is the relatively OCF version of two of the hard reflectors that are very inexpensive and far more portable designed to work with the B1/B2 or actually any of the flat-front lights.
All photos SOOC via Lightroom CC. Made with a Canon 5DS R with 24-105L f/4 and 100L Macro as well as the Fuji XT1 and 55-200 XF and various combinations of the Profoto B2, D2, D1, and Pro7 head.