I agree. i'm finding Cubasis to be a great Multi track with built in sequencer but the magority of instruments used in my recordings so far are using sounds from SampleTank, Alchemy, Sunrizer and Garageband. I have an iPad and iPhone so I do sound out from one and bring it into the other via Mobile In interface.
The sounds in cubasis also seem to have a distinct sweet spot. In other words, select a vocal Ahh sound and it sounds fine within 1-2 octaves but above or below that it sounds horrible. It's like the sample is noisy and waveform is breaking up. Same goes for many of the synth leads in the higher register. Get very gritty to the ears.
I look forward to some form up improvement in this area.AND also Audiobus implimentation.
iPad 2, iPhone 5, Mac Mini
iRig Keys, iRig Mic, iRig guitar, You Rock Guitar (midi guitar) Mobile In Guitar, GarageBand, Alchemy, Sunrizer, Cubasis, Music Studio, Amplitube, Mobile POD, MultiTrack, bs-16i, SampleTank, AudioBus, AmpKit, JamUp XT, G2M
Epiphone Les Paul Special GT
Music For iPad