Drinking beer releases man-made CO2 into the atmosphere, which causes all bad things to happen. Excessive consumption of beer, in its self, causes many calamities, bad combination. If you need something to remind you to buy more, perhaps you've already had too many... I usually keep a 6-pack of bottles in the frig, mostly for company, but occasionally one or two is nice, after working outside all day. Even in my younger days, I was considered a light drinker. I also keep a bottle of Canadian 'Toothache' medicine in the house, going on 6 years, and still about half full.
I'd go with measuring the weight, you won't have switches to wear out or keep clean, or worry about exact placement of each beer, plus it can easily be adjusted to what ever volume you use. I don't drink enough to worry about it, but if I really want one, there are two bars, and a convenience store just two streets over from my house, easy walk, and can even bring my dog...