I do not work with these at all. I dislike the look and function.

A well designed shower does not need them at all.

Same here, Mr. Whipple!

If you have hard water, I can promise you that the now "clear" plastic over time is going to become brown, and look disgusting. Hard water, and cleaners cause this.

I am a Journeyman Glazier that has designed and installed over 4000 over the course of my career. The images you show are "gaskets" and door sweeps.

Generally speaking, a custom frameless shower should not require these, other than perhaps a door sweep if you are not in the habit of pulling the door slightly inwards to prevent a small water pool after each shower. Industry standard for glass sizing variation is 1/8", meaning that gaps should not be any larger than that. Mine are generally 1/16". If you have large gaps, someone made an error measuring (or doesn't know how to properly) and you should not be required to accept the work. A LOT of contractors try to get around this by using u-channel so they can hide poor measurements. A true frameless shower does not use u-channel, so if that's all they use, find another contractor.

One exception to this is if you have a hinged, two piece "shower shield" which hinges glass to glass close to the shower head. If you spray or pour water down an open seam, it will come out, so try to either hinge the panels behind the shower head, or make the first panel as wide as you can, and use a rain head whenever possible to minimize outward spray. A regular shower head + a large person + shower shield are not a great combo and may require a vertical gasket for even a very small gap.

Images below, including a u-tube on how a shower door should close (without gaskets).

What a frameless shower door should close like!

Tub / Shower glass panels & shower shields, Vancouver Shower Glass Professionals · More Info

Mine has only the bottom sweep, nice tile selection by the way.

A good glass cutter should be able to account for the uneven walls etc. ...

Not true. Walls must be straight and plumb. That is basic standard construction. Glass doesn't bend, and cannot be scribed to fit like it was a molding hiding sloppy work beneath. Your sins are all out in the open and visible with glass. Make sure the framer isn't the lowest paid member of the crew, as it all starts with him. If the studs are bowed and warped, your top layer won't be any better.

Most doors do need a sweep on the bottom to prevent water from running off of the curb. We don't use vinyl strips any other place because we measure really well for out of square conditions. That being said- we do reject openings that have outages greater than 3/8". If the tile is redone to correct outages before the glass is installed leaks and crooked looking glass will be avoided. Hire a great tile person, it's well worth it! : )

Nicely said, Hillcrest Glass. A good tiler will save you in the long run!

A quick comment about (bottom) door sweeps, they can be very helpful but require a minimum clearance at the floor. If your existing shower looks like it is short by 5/8" or so, it probably was measured to accommodate a now missing sweep (a cheap fix).

If it's making a noise, check to see if it needs to be pushed up a bit, or better centered on the door.

The trims are normal, specially the drip seal at the bottom , if you want to have the outside of you shower space dry. We put it in most of our hotel projects, including 5 star hotels. Personally I don't like them but they are a typical requirement for most hospitality projects.

If you use any of the common wall to glass hinges that would automatically be a 9mm gap from your glass door to the wall tile just because of the config of most hinges (dormakaba, hafele, etc...) and that gap will be enough for the water to go out if your shower room is tight

I have a small gap at bottom of Glass door and a door sweep won’t fit. Any suggestions?