I agree with Claudia that Nundah has come a long way. When I first moved to Nundah over 20 years ago the area definitely had a "good side" and a "bad side". This was largely due to low cost housing and working class stigma attached to the area some locals used to call Nundah Flats (it is a predominantly flat area east of the train line).
This same area has now seen quite a bit of reinvigoration over the last 10 years or so. There's been countless renovations of homes, plenty of new contemporary family homes, new unit and townhouse developments and its arguably an easier (flat) walk to and from Nundah Village, the train, the footy club, local coffee shop and a very friendly family focussed primary school. If you need a car to get around there's also multiple options to head north or south, quick & easy access to the airport, gateway arterial, and the list can go on and on.
Some of the old school locals will still tell you where they live in Nundah is better. And if you want to spend the money you'd possibly live on the hill with bigger blocks and less neighbours, but it's all a matter of perspective. I have lived in 3 different parts of Nundah and they all have been great for different reasons.
Feel free to drop by Ray White Nundah for a quick introduction to our wonderful suburb next time you're in town.
Nundah has definitely come along way over the years with a lot of new developments throughout the suburb. I wouldn't say there is a bad side of Nundah, but i would be looking to purchase closer to Nundah village and not down the end of where Nundah train station is located.