I gave a lot of thought to Bratislava, and made many exploratory visits there over the last ten years, but I'm not convinced at all regarding residential property there. Some investors, like Sean Mulryan, are going in there very strong, but I wouldn't like to be a small player there.
On the plus side, Bratislava is close to Vienna, and a steady enough stream of Austrians go there on Friday afternoons and saturdays to shop. Tesco bought the old communist department store several years ago and it is a goldmine for them, with a good percentage of Austrians coming throught the door at weekends. There is a need for good small commercial in this area and probably in the future around where Mulryan is building, for rent to gift shops, phone shops etc. Such places are hard enought to find though.
If you take a walk up the hill to the schloss and look across the river, you will see a huge communist era housing development of high rise apartments. This project has some of the highest rates of divorce, suicide, unemployment, depression etc in all of Europe, and you need to be a far away as possible from it if you are looking to buy residential.
The other problem about apartments in this city is that they can be as expensive as Prague or Budapest, mostly because foreigners are prepared to pay these prices, but they just don't compare in investment terms.
My advice is to be very careful what you buy in Bratislava, and to avoid residential if at all possible.