I try to always use wide mouth. I find them easier to pack and easier to clean. However, I do have regular mouth as well. They are mostly used for things like tomato juice and salsa and things that are not packed. It seems I always have both kinds of lids and rings around because I use alot of jelly and half pint jars.
I like both also. wide for green beans and pickles and such...easier to get out, and small for tomatoe juice. My MIL makes tons of mater juice and she mentioned that to me, that juice pours better from the smaller mouth.
nice things about the jars they are reusable over and over again.
I like the regular mouths for anything that pours. I like the wide mouths for anything I have to pack, easy in / easy out.
I also have 3 blue 2qt jars and 1 clear two qt jar. They are really not much good for anything since they wont fit in either one of my pressure canners. :/
I use both also. I love the wide mouth for making yogurt, packing fruits, veggies, pickles and for storing mixes. I use the regular for honey, jams, butters, tomato paste. They are also good for storing those decorating items, like sprinkles and dots.
I use both. It's partly because, like poppycat, most of my jars come from 'wherever' and are a mix.
But chiefy I keep the narrow-mouth quart jars around (rather than gradually getting rid of them as I get more wide-mouth) because I do at least several dozen half-pints of jellies/jams/marmalades per year and thus HAVE to have lots of the smaller lids in the cupboard. Since the lids are there anyhow, there's always some around for the narrow (non wide) mouth quarts. Yet I can't go to all narrow mouth quarts and get rid of the wide-mouth ones, because I am not really into elaborate ship-in-a-bottle games when packing food or trying to get it back out again
Like everyone else- I use both for the same reason. I also store things like nuts and grains in them too and the small mouth work well.
The one thing I can add is that regular size lids are a bit cheaper than the wide mouth.
I keep the bands sorted in two large, old glass strorage jars- then it's easy to grab the one I want.
Wide mouth jars are great because they are so easy to pack , so when i buy new, I buy wide mouths, but most of my canning jars were inherited ( yay , free ) and are narrow mouthed.