Hi -- I can only give you our personal experience and our opinion.
We have left Singapore in July so our experience ends at that point.
We noticed that the school increased in size dramatically over the last 2 years (was 600 now close to double that I believe), and that hasn't been easy on students. Students were previously very carefully screened as they entered, to identify any special help they might need... parents tell them this has changed.
Also Teacher quality used to be the best thing about the school. They were excellent. But we have seen the experienced teachers leave over the last 2 years, and much "greener" ones replace them. While some of these new teachers are ok, the quality wasn't consistent anymore. This was a real issue for our children -- but we knew we were leaving in July so finished the school year there. (they had been there for 5 years)
However, there is a new principal just started in August. , and a friend who works in the school tells me that now things may be improving in small ways-- the new principal is "bringing back homework and spelling" into the primary school, for example. So, it's possible that the principal who came in soon after Nord Anglia took over (came about 2 years ago) may have been part of the problem?
Personally, I would ask specifics: on class numbers (not just averages) , about the teachers (how long they have been teaching and how long at Dover Court) , homework policies,etc. Unless you just plan to stay for a year or so, then all that might not be so important?
BTW, There are other British system schools in Singapore, including Dulwich and Tanglin. And then many many other
International Schools. All the best!