Pick by what happens to the pipe on a normal day. If it rides in a bag or gets passed around outside, that points one way. If it mostly stays home, that points the other.
The short answer
Choose silicone if the pipe travels or you have broken one before. Choose glass if flavor and looks matter most. Many people end up owning one of each. A silicone pipe still has a glass or metal bowl where the heat is, so no good pipe is silicone all the way through.
Durability
This is where silicone wins clearly. It bends and takes a drop that would end a glass spoon. The bowl insert is the part to look after, since it can still break. Thick borosilicate glass holds up better than people expect, but a hard floor usually wins.
Flavor
Glass does not add any taste of its own, which is why people who care about flavor stay with it. In a silicone pipe, the smoke touches the glass bowl first and then the silicone, so buying from a brand that uses a proper glass bowl matters.
Cleaning
Glass handles an isopropyl and salt soak and comes back looking new. You can also see exactly how dirty it is. Silicone comes apart and flexes, which makes residue easy to pop out, but it can hold on to smell longer. Check the maker's care notes before soaking any silicone piece in alcohol for a long time.
Which to look at
For silicone with glass, look at the Softglass Core Hand Pipe, the small Token and the Core Bubbler, or see all Softglass. For glass, try the Human Grade Fleur or Rainbow Spoon, or browse hand pipes.
Questions people ask
Is a silicone pipe safe to smoke from?
Look for one with a glass or metal bowl, so the heat stays away from the silicone, and buy from a known brand.
Does a glass pipe taste better than silicone?
Many people find it does, because glass adds no taste of its own.
Which is better for travel?
Silicone. It takes knocks in a bag that glass may not survive.
See them in person
Come feel the difference at 1321 at 1321 Venice Blvd in Venice, CA, open every day from 11AM to midnight. Availability shows on each piece.