I live there! Moved in two months ago with some friends who bought a house on the road. It's grand. Handy for town because the 40 zooms in on the bus lanes, takes just 20 mins to city centre even in rush hour. Brilliant leisure centre down the end of the road and all the shops are within walking distance. It's a good location because there's a park in front so there's no fear of it being built on. Our neighbours are lovely although the road can be quite busy - the speed bumps stop any boy racers though. And this might sound silly, but the houses are facing the perfect way. Sun on the front in the morning and in the garden in the evening, perfect for weather like this.
That said, I'm only there temporarily while I wait for a sale of a city centre property to come through for me. While the area itself is grand if you go a few roads back it's not. There's gangs of kids hanging around who can be quite intimidating if you're out for a walk. And if you get the 40a or b out it goes through some seriously dodgy estates.
If you're looking for an investment property or somewhere to live for a few years before trading up I'd definitely go for it. I've heard that they're moving Finglas village a bit closer to the M50 and are building a whole new town with the biggest Dunnes in the country. Also, because they're ex-coundil houses they would have had an engineer on site so they've very well built. It's an up and coming area and I think there's going to be a lot of capital appreciation there over the next few years.
What kind of bad things have you heard?