Mike,
I tend to agree with trackfood on those cans. We all need the flexibility to run our business the way WE think is best and I certainly do some things that other business owners wouldn't, but... I think those drink cans are hurting you.
I assume that they are 12 oz cans in general. I have one size drink that small - child size. These are mostly sold in the kids packs although some go out alone to kids (and occasionally seniors). We sell them for $1.25. Every other drink we sell is therefore more than that and we sell a lot of them. I think that our biggest number of units sold goes to medium size - $2.00, but that is very closely tracked by jumbo size - $2.75. Like you I try to have a huge choice in flavors - current choices on the pop machine are: Pepsi, Diet Pepsi, Dr Pepper, Mountain Dew, Sierra Mist, Mug Root Beer, Orange Slice, Pink Lemonade and Raspberry Iced Tea. We also offer Grape Punch and Fruit Punch in one of those old fashioned refrigerated bubbler machines. We occasionally sell bottled water($1.00 and $1.50)and juice boxes $1.00.
Since I am the one who does most of the drinks, I know where you are coming from on speed and foam. When I am working HARD I usually have two orders filling at the same time. I can place 8 drinks on the pop machine at once, but of course no one orders the right mixture to do this. I have 2 pepsi spouts so can fill two at a time. Pull those 2 off and set on counter to wait for foam to clear while filling another 2 pepsis. Pull those off, top off original two drinks, then lid and give to customer. Check last two, refill, lid and give to customer. Since we work as a team, the popcorn order is being done by someone else and the money has already been collected. The customer is told to step over to the drink side of the counter where I give them their drinks and finish the rest of the sale. Make sure they can find straws, offer trays to share popcorn and generally make sure that they got everything that they ordered and all is OK. Four of our drinks don't have foam problems so that makes them a tiny bit quicker and 2 drinks won't fill if the pop machine is repressurizing so that requires extra management of time. We know that getting the drink orders first is critical on the kids packs so everyone has instructions to extract the drink flavors first from the kids before showing them the candy choices. Our syrup setup is just below the counter, so that we can keep an eye on it. Low bags are hung up on a rod so that they don't get air in the pipes and cause extra foam or filling problems. 2 pepsi spouts is a must because that is the one most likely to run out and give you problems. I just cease to use the one that is running out until I can switch the nozzle to the new box which is already in place when the bag from the previous box was hung up on the rod.
After typing all of this I hope this is understandable. I don't know if I have helped or hindered you but I hope that you will reconsider the can issue.
BTW, I remember that there was a discussion of Pepsi vs Coke in which part of the problem was which supplier would give you a machine free. We had an interesting experience with that when we opened. I think the two companies go through phases in which they are more or less willing to give free machines to new setups who use their product. When we opened we had a 4 head pepsi machine that came with the business. We weren't willing to limit ourselves to 4 flavors so we contacted both Pepsi and Coke. Since my husband had worked for Coke for 11 years and knew people at the local bottler you would have thought that we would be selling Coke. But no, they wanted rent for a machine and some other restrictions. Pepsi was no better, I think they wanted $120 per month rent on their machine. So we did a favor for one of the other local theater owners for whom we had worked previously and they let us choose a machine from their warehouse of uninstalled Pepsi and Coke machines taken from closed theaters. We chose a 6 head Pepsi machine and called Pepsi to come out and install it. They came checked the serial number and said that that was one of "their" machines. We said that they couldn't charge us rent on it since they had abandoned it with the other theater owner. They agreed, installed it and we have been a Pepsi account ever since. Some time later we got them to install a tower (2 unpressurized spouts) and then they gave us a brand new 8 head machine with the proviso that they weren't taking back any out of date syrup. Hah! Like we ever overbuy on syrup. Of course they didn't want their 6 head machine back this time either, so I have an extra pepsi machine at home now.