In the mid 1990s a couple of cheap and cheerful dumpling houses opened in the CBD, with Tattersalls lane being a focal point. Popular with university students it slowly gained momentum as a communal meal through to the early 2000s. Around that time more restaurants started opening with quality and price slowly improving. Unfortunately the original restaurants have dropped in quality and cheerfulness, instead favouring cover turnover speed and maximsing business.
Luckily a couple of speciality stores have opened, including I Love Dumplings, Hu Tong and Shanghai Street Dumplings which continue the cheap and cheerful vibe.
For your daily yumcha, there are plenty on offer on the weekend, from the very formal (sitting times) to the more random.
Dragon Boat in Little Bourke St gets a mention for doing yumcha rain hail or shine. The food and prices are above average, the wait staff are pleasingly surly in that way that only disinterested Chinese wait staff can be - see #notallchinesewaitstaff for more info - and there are the hits of the sixties and seventies being played on traditional Chinese string instruments on the tinny radio. It's open early on Sundays and there are no sittings - you just have to get a table.