I have used HC-110 for about 10 years now, mixing directly from syrup, and I really like it. Once you get used to pouring the stuff into a small graduate, it is really easy. I pour the syrup into the graduate, being very careful to ensure that I do not hit the sides, which will throw off the measurement because of the viscosity of the syrup. I also make sure to rinse out the graduate with the water I am adding, at least 4-5 times to make sure I am getting all the syrup. The hypodermic method suggested by Covington works well too.
The only problem I had with it was in my Jobo for zone system development with sheet film. In order to keep the development time from creeping under five or even four minutes, for N-1 and N-2, I had to go to higher dilutions. Not a problem, except that the Jobo only holds so much and I don't think the motor likes the tank filled right up. I now use Expert Drums without the processor (hand rolled in my darkroom sink) and that method allows me to use highly dilute solutions, like F (1:79).
I have never been able to find anything from Kodak which indicates clearly the minimum amount of syrup per unit of film, so here is how I figure it. The Kodak data sheet says that one gallon of dilution B will process 10 sheets of 8x10 film. One gallon is 3785 ml so one gallon of diliution B would contain (3785ml / 31 + 1 ) = 118.28 ml of developer, which develops 10 sheets of 8x10. So one sheet of 8x10 would require 11.8 ml, rounded off to 12 ml. One 4x5 sheet would thus require 3 ml. I once calculated the surface area of a roll of 120 film but I can't remember how I did it. In any case, based on that now-missing arithmetic, I used 6 ml per roll of 120 film. I suppose I could just measure a developed roll!