hi, I know New Malden quite well. I have family there. If you want me to be insanely honest, this is what I think of the area:
Pros:
It's outside Wimbledon (quite far out though) and a lot of people in new Malden like to tell people who don't know the area they're "near" Wimbledon, to look good by association (but there is no association really).
People who are priced out in Wimbledon, Surbiton and the nicer parts of Kingston/Teddington try New Malden as their plan B/C area.
It has a couple of parks that seem to be well kept.
I don't know about the schools, but they might be deemed "good".
There are some nice houses there - semis and detached.
It is a diverse area with a lot of Asia diaspora (korean, south asian) and I won't be surprised if it officially becomes a Korea-town soon because it has the largest Korean pop in the whole of Europe! there is even an estate agent called Seoul properties lol, it's fantastic!
The high street "looks" nice if you're in a car. There are your usual chains like cafe nero, costa and there's a waitrose (which imo is over-priced and pretentious).
Cons:
The biggest con: it is right next to a massive, hectic, noisy and polluting A-road (the A3!!!). It is absolutely awful and with all the research now about pollution and its risk to health inc children's health it is not an area i would even consider.
The houses are over-overpriced for an area that doesn't offer much. It's mainly just has a residential feel, rows and rows of houses and that's all.
Unfortunately, My family members were burgled - TWICE. the second time their internal cctv recorded the burglary with the men's faces and everything and still to this day no one has been caught.
The high street is tight and quite small, but adequate and if it weren't for the trees, it would look like a dump. when the road running through it is busy (which is often) it just feels like a massive stress and just an extension of the cars coming of the A3, which many do. It's no different from any other high street in london really. it just has the usual chain restaurants and cafes and nothing exciting tbh apart from the many korean takeaways and restaurants popping up like every week (i love k-food and this is a strong point really )
i would look around the area for a few days and at different times of the week before you decide.