My RB 1000 worked for almost 3 years before the caps failed however I have had a RB333 fail within a week of service so there is no timescale. If your boards have these caps they will fail there is just no telling when. Hence I do not take the gamble and swap caps before deployment. It seems there are still a lot of Boards with these caps in circulation as I have just received another RB433 from my supplier with the them on board. Honestly, if you can use a soldering iron it takes minutes to swap them, replacement caps are only a few cents each. Much cheaper that returning them to the supplier.
I use Nippon Chemi-Con 820uf/6,3V 105ºC caps from
http://www.diyaudio.esNone of these have failed as yet.