Latest craigslist hunt in Apr. 2013.  The current ultimate GK modeling multi-effect processor.  This thing can do alot.

Roland's flagship bass processor came out in around 2009.  Dual COSM processing engine which means you can have 2 independent signal chain(sounds) stacked to form the 1 patch.  Which is not something new as in 2013.  However, with a GK equipped instrument(GK3, GK3-B divided pickup) through the 13pin cable.  This box can do the following things:

- polyphonic synth, a synth that works

- bass/guitar modeling, it has upright bass, a few electrics such as jazz, precision, musicman, gibson, hofner, and other custom setup.

- a multi-effect for the bass's magnetic pickup itself

plus you can blend any of the things above.  pretty much everything is tweak-able, way too much imo.

The thing it doesn't do:

it is not a have PCM bank, it doesn't have sample libraries for things such as piano, horn, and other samples or sounds.  You'll required an external sound module / or laptop.

By the way, the tracking on this is flawless, there's no noticeable latency.

Might need to spend quiet sometime playing around, thanks for checking!