Hi!
I using the Abacus for 11 months now
6 nights a week ,no problems!
It is based on a Windows PC with DSP hardware for sound creation and a multitude of big programmable pushbuttons and sliders and a big color touch screen.The sound is huge and true to life ,sounds are kept on disk and are 100s of Mbytes.I use normal Windows programs for MIDI and Audio Sequencing,Wave Editing,MP3 creation and playback,CD writing etc.I also have installed the Styleworks program so I can convert all style formats but mainly I convert MIDI files to Style.Number of styles ,SMFs and Waves are only limited by hard disk space which is a standard 40Gb .I have also a second Hard Disk (copy) just in case but i never used it.
The whole thing is software upgradeable -CD ROM-and the new version 4 allows to use Gigasmpler(!) and Native Instruments as sound sources.In a few words:
I dont thing there is something that another keyboard can do that the Abacus can not.
And to my audiences ears (that includes a lot of musicians from all over the world)
it sounds fantastic!