Town centre is lovely - lots of wee local businesses and there’s a real small-town, busy buzz around the centre.
BUT - it’s known as Loyalist Newtownards for a reason. Even the nicer areas, which may not have the more obvious flegs, have a presence.
Also - in terms of commuting to Belfast - you’d be driving through Dundonald every time and I’d do anything to avoid that. It is surely the slowest town to drive through - rush hour or not. There are buses around the town and down the peninsula, and into Belfast, but the bus is your own option as Ards isn’t on the train line.
I’d choose Bangor over Ards any day. Yes - the town centre is run down and the council does seem to have a bias towards Ards, but as a town as a whole it is so much nicer. It is still a largely Protestant town, and there are clear paramilitary strongholds, but if you avoid those areas, then it’s a much more pleasant experience. You are also on the trainline which I think trumps Ards every day of the week for the easy access to Belfast/Holywood etc.
In terms of schools - some very good primaries in Ards - Victoria, Model, Londonderry, Castle Gardens, Abbey - all got good reputations. For secondaries you have either Regent for grammar or Movilla for high school, or you go down the peninsula to the likes of Strangford/Glastry/Nendrum. Regent is very large, and has mixed views - headmaster is not popular (I don’t know a single person who likes him and I have a lot of friends who are parents with pupils at the school and also know several staff) - but you’d expect him to be gone by the time your DC get there. Movilla has definitely improved in recent years, but I’d never send my DC there. It also only goes up to 5th year, so if your DC wants to do A levels then they have to leave and go elsewhere. (Most seem to move to either Bangor Academy or Strangford) Having said that, it has the potential to keep improving and could be very different by the time your DC get there. It desperately needs a new building though if it’s going to survive - it’s very run down.
Bangor has 2 grammars - BGS for boys which has a good reputation (certainly much better than it did 20 years ago), and Glenlola for girls which doesn’t have a great reputation at present, (and I wouldn’t choose it), BUT I know a lot of girls who have been very happy there and have done well. For high schools you have Bangor Academy which is enormous, but with an excellent reputation if you’re not put off by the size, or St Columbanus which is much smaller, more run down and much more limited in subject choices. BUT - because you’re in Bangor - you have much easier access to schools in Holywood or Belfast whether for Grammar or High School. Primaries in Bangor are mostly all very good.
House prices in Bangor are going to be higher than in Ards though.