very happy with them in xo.. also bear in the mind the humble hifi capacitor comparisons/ratings are in the context of speaker/crossover use, not electronics...
1uF might be ok for your DAC, it's basically setting the highpass filter in combination with your load impedance, if your load is fairly high impedance (say 50k) 1uF will still give you a 3.2Hz corner, which is plenty low.. (2.2uF is 1.4Hz in this situation)
Also, I sold a pair of 3.3uF Alu foil/PIO to Steve M in Perth to use in his Scott T DAC, maybe ask him for his impressions?