Put me on the list of Used-To-Be-DIY..
Compressed gas is:
cheaper (see sugar cost comment)
also cheaper if you pretend to bill yourself to the time keeping DIY running.
barring any clunky regulators, you're going to see the same Bubbles/Second rate for a long, long time - when I was DIY, I was pretty 'meh' about whether or not this matters. After a month or so of being on compressed gas, it felt nice, when troubleshooting, to be able to rule my fluctuating CO2 levels as a possible cause for whatever issue I was trying to solve. In retrospect, I didnt' realize at the time how much it short-circuited my problem solving.
Well, for me it is. I went from a 2-liter outside the tank and a reactor inside to a paintball tank direct-feeding into one of my filters (magnum 350, impeller on the bottom keeps fears of airlock at bay!).
another "i didnt expect this to matter" point. The reason I had the reactor in the tank was that plumbing it inline meant the yeast culture had to 'beat' the inline pressure. It was certainly capable, but the bubble rate was erratic, and made it very fiddly to keep a good count running.
all kinds of glitzy gee-gaws:
now i can oogle glassware in a new way. I wonder if that's a /real/ ruby in that ADG check valve...