Just hit Guilds. Looked over the list.
Arsenale - That's pretty friggin tempting, 15% production and 10% naval strength?
Glassworks - 2 food and Tourism per Great Person and Village?! That's... it's nice, but not as good as the Arsenale. Artist specialist and 5 science Theming bonus are... eh.
Rialto - Oh gods 3 gold incoming and outgoing? AND extra delegates for money?! Hhrrnng how do I pick between this and Arsenale?
Glassworks needs something to compete with the other two. I get that it's geared towards Culture victory, which is my least favorite victory, but Great Works and theming bonuses are not the big Tourism generators in CBP. Maybe a Culture one time yield for completing a trade route with a major civ?
I think the other two are in a fun and interesting place. It's a REALLY tough choice between them, and they lend themselves to different playstyles.
Although, I would disagree, Glassworks does need a buff. Unlike the other two, Glasswork doesn't have a "global" effect except providing tourism.
Because... this

should look like a global change such as
