Meanwhile Belgium has nearly 50% dual-stack IPv6 deployed and there haven't really been any issues. It's configured well and works well. The vast majority of users probably hasn't even noticed.
The is one advantage of having an active duopoly [1] in the ISP market. Belgacom (38% market share) started migrating customers to dual stack in 2013. Telenet (40% market share) soon followed in 2014.
[1] http://www.broadbandtvnews.com/2015/03/20/telenet-belgacom-s...