As the redevelopment began on the £29.5m extension to the Waterfront Hall many were sceptical, with some dubbing it the "Box on the Docks" and the "Sore on the Shore".
Many complained that a new extension was not in keeping with the original circular structure or the surrounding area.
But there was a turn in opinion following a sneak peek in January where the new design proved a hit.
Belfast Waterfront has doubled in size to create an international venue capable of attracting major conferences with a fully flexible and integrated space catering for up to 5,000 delegates a day.
It aims to generate £100 million for Belfast and create 1,500 new jobs by attracting 50,000 conference delegate days each year by 2020. The first major conference will attract over 1,000 guests and bring in £2.2 million for Belfast through bed nights, transportation and other visitor spends.
Those behind the project say the effects of the investment are already being felt, with over ten new or extended hotel projects in the pipeline.
Hall 1 is the biggest section at 1,805 square metres. Hall 2 is smaller and more intimate, with windows along one side allowing delegates to see across the city. The building also has meeting rooms upstairs for smaller events.
The extension is kitted out with state-of-the-art technology, providing great sound quality, and the modern fixtures and fittings have been finished to a high standard.
Thirty international and national conferences have already been secured for the next three years - among them the BBC Good Food Show, the World Council of Credit Unions and the Royal College of Nursing.
The official launch comes just ahead of of next week’s NI Chamber of Commerce dinner, which will be the first business event at the newly transformed riverside venue.
Lord Mayor councillor Arder Carson said: “Like the original decision to invest in the Laganside area back in 1997, the new look Belfast Waterfront in 2016 will elevate our city’s global profile, bringing growth, prosperity and opportunities to Belfast and its people. It is a cornerstone of our vision for city centre regeneration and will add to our reputation as a vibrant global brand.
“Visitors want to come here, thanks to our warm welcome, history, culture location and international reputation. We expect to get 50,000 delegate days each year by 2020 because of the new facilities, and two thirds of those are expected to be from out of state - bringing in an £45 million per year for the local economy each year from 2020.”
“The boost for our hotels, bars and restaurants will potentially create 1,500 jobs in the hospitality sector, bringing opportunities, particularly for our young people,” added the Lord Mayor.