That is correct. It's not quite as convenient as a monolight where you simply dial down 1/3 of a stop, BUT... once you become familiar with using a pack & head system, it works like a charm. Speedotron Brownline is my primary system and despite now being a position where I could afford much more stylish gear, I have stuck with Speedo, and likely will as long as they are around. Quality-wise, it's hard to beat. All metal, super strong mounts, a virtually fool-proof mount for modifiers... his stuff is built to last and last and last.
There are a couple of less positives as well of course... Speedotron isn't the most common modifier mount, so if you're looking for soft boxes, beauty dish, etc.... you might have to look a little bit, but it's available. As well, pack & head systems aren't as immediately initiative as modern monolights. They're designed for portrait work where everything was about ratios (eg, key one stop above fill, etc), and once you get that squared in your mind, it's dead easy. Minor adjustments (<1/3 stop) are often made simply by moving the light six inches.
My favorite thing about them is that they're a small company and this is all they do. They also answer their telephone. A few years ago I needed a new 'Push to flash' switch for one of my power packs; I called Speedo in Chicago, a person answered the 'phone, and in less than five minutes had taken my information, CC # and the parts were in the mail. No 'phone tree, no "We don't sell parts" or lectures on voiding warranties, just, "One switch.. that'll be (some very reasonable price I can't recall).
I'm a firm advocate of them as the absolute best deal in professional lighting today. I currently have five power packs and over a dozen heads. Everything on my website (link below) that was done with a strobe (with a few exceptions which are speedlight work) was done with Speedo Brown.