For starters, the 4 voice synth engine is solid and has the ability to create some amazing sounds that span the entire audio spectrum from gut churning basses to angelic and ethereal pads. That said, the 128 presets that it ships with are pretty decent to get you started, but PLEASE refrain from using them in your recordings/performances without doing a decent amount of tweaking and effecting. The mK seems to have a very unique sonic footprint, and since so many people own this synth, using the presets as-is is definitely going to be frowned upon. Of course this can be said about any synth, but especially for the microKORG.
There's nothing quite as anticlimactic as seeing a band perform live using the mK and you recognize they're using factory preset A43. The built-in delay/ensemble effects are great, but I think the mK sounds 1000x better when ran through some outboard effects. If I want a sick and meaty low-end bass, I'll run the mono output of the Korg to my fuzz pedal and then directly to the board or to a bass amp. It's pretty filthy. Editing and tweaking your own patches is easy enough via the seven knobs and 3 character LED screen, but it tends to be a time-consuming process, especially since there's no visual feedback of your tweaks. If membrane style programming isn't your bag, then you should definitely download the free, but since the mK lacks USB connectivity, you'll need an inexpensive USB/MIDI cable. 28 November 2011 Written Update Of Ipkknd Hot.
Both the MIDI implementation and the editor are a tad wonky, but you'll be able to visually access and edit all of the synth's parameters. Adding to the functionality, once you've made your connection, you can sequence the mK from your workstation (Ableton, FL Studio, Sonar, etc.) via MIDI out. This of course, opens up a whole new world of possibilities and will really let you unleash the power of the microKORG. Finally, since the synth engine is same one used in the Korg MS-2000, you can import MS-2000 patches into the mK by means of sysex files. You'll need a MIDI utility such as MIDI OX, and from there, it's gets a little complicated. Truth be told, this was a key factor in my decision to purchase the mK as I wanted it for live vocoding. Software/VST vocoders are great, but they tend to be process hogs, especially in live situations, so for this reason alone, I insisted on the hardware route.