In the past, I'd lugged home plastic bottles of effervescent flavored waters from the stores. Again, and again, and again --day after day- week after week- month after month- year after year .... I'd lugged them up the stairs and into my home. I'd found the need to make space for the extra bottles in hopes that that I could do the 'toting' chore less frequently.
It takes moments to tote the empty carbonator into Best Buy to do an exchange. It's then MONTHS of toting:
I'd used siphons for many years [--in the decades before the ease of internet/Amazon, etc], but bored with the inconvenience/difficulties to find --and to keep/have on hand- the needed chargers
ONE trip to tote 1 or 2 cylinders (I have two cylinders, so that I only need to exchange -at most- 2-3 times per YEAR )
NOT a terribly tricky decision here., eh? ;-)
An a different tangent:
For those trying to kick the cola/soda habit, may I suggest the simplicity of picking up freshly squeezed orange juice to which you can add your SodaStream soda?
And/or, the ever-handy frozen pineapple juice in the freezer? It quickly becomes so much less cloyingly sweet when you put a tablespoon into a tall glass filled with soda/turn it into a spritzer