problem with these software synths is always the latency. Sure it's simple to install the crap and load in a driver, hook up the midi.. but for live play, the latency (ie. the time it takes for an actual sound to be heard from your speaker set after you pressed a key on your keyboard/midi controller) tends to be too many milliseconds for these to be of any real use. ASIO compatible sound hardware is of course mandatory, but even so, latencies will vary hugely. You need to invest in very expensive dedicated sound hardware to get near-zero delay.