Thicker glass. Best hinges. Warranty. Inside of glass can have special coating to help keep clean. Buy a squeegee and use after every shower to help keep the glass pristine.

I'm a Journeyman Glazier that has installed 4000+ custom frameless showers. Go with someone who does these installations regularly, is actually a trained Glazier, and that doesn't uptalk you into unnecessary add-ons like water resistant glass (you only need a bottle of glass sealer). All hardware should be solid brass in your chosen finish - not u-channel.

Ask what his typical tolerances (gaps) are. If they say they use u-channel, or accept gaps more than 1/8", they don't know what they are doing.

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