Most bong comparisons stop at beaker versus straight tube. Round base is the other common shape, and the choice between it and a beaker mostly comes down to where the piece lives.
The short answer
Get a beaker if it will sit on a table around other people, because the wide flat bottom is harder to knock over. Get a round base if you want a lighter, more compact shape that is easy to pick up and pass. Both draw through water the same basic way. The shape changes how it sits, how the water moves and how you clean it.
Stability
A beaker's cone puts most of the weight low on a wide footprint. A round base has a smaller contact point, so most rely on a flattened bottom to stay upright. If you have a busy coffee table, this is the difference that matters most.
Water and the pull
A beaker holds its water across a wide area, so it can take more volume. A round base holds less and keeps the water closer together. Fill either one just enough to cover the downstem. Too much water means splash, whichever shape you pick.
Cleaning
A round base has no corner where the wall meets the floor, so a salt and alcohol shake moves around it easily. A beaker's edge takes a little more shaking. If low effort cleaning is the priority, we also wrote up the easiest bong to clean.
Which to look at
For a round base, start with the GRAV Medium or Large Round Base. For a beaker, compare the GRAV Mini Beaker, the Medium Beaker and the Human Grade 9 inch. Everything else is in bongs and water pipes and GRAV glass. Weighing a straight tube too? Read beaker or straight tube.
Questions people ask
Is a beaker more stable than a round base?
Usually, yes. The wide bottom gives it a bigger footprint.
Does a round base hit differently?
It holds less water, so it can feel lighter to pull. The downstem and overall size matter as well.
Which is easier to clean?
A round base, slightly, because it has no corner at the bottom edge.
See them in person
Shape is easier to judge in your hand. Come by 1321 at 1321 Venice Blvd in Venice, CA, open every day from 11AM to midnight. Availability shows on each piece.