My mate has one. It has some pretty cool effects but the amp modelling is pretty meh.
Got on the bus with me daysavaaaa
I've got one, i love it. The weekest parts of the unit are the cab models. They do sound slightly digital. The reverbs aren't quite long enough but a bit of delay overcomes this. The delays however are very good. It does have it's limitations though as you can't use say the marhsall jcm 800 model and then add the tube screamer model onto patch at the same time. Some people have complained about tha lack of gain on the unit, but i've found there's enough for me and i play shred style. The people that are complaining should probably learn how to play better!! I also have a Zoom g2 unit, and the Korg unit is much better, although the Zoom unit has a nice harmonizer and the chourus is is a bit nicer. The prices are dropping now and these units are pretty cheap. I'd recommend you check one out and also try one of the other modelling units and see which one you like best.
got one, great piece of kit, about £125.00 or thereabouts new.. looks complicated but very easy to use, and an excellent wah pedal.. originally retailed at £180.00 !!

Have a look at the korg website for some demos etc..
Played an AX5G which is basically a smaller one.

it does what you expect... But don't expect much quality. The models all sound horribly digital and muddy. Wah is horrific. Delays etc are okay.... I'm against multifx boards, but if you just want something to play around with tonewise, there's better.
The Laney Thread are big and clever. No exceptions.
I've been using an AX5G with my VJ head - mostly to add Reverb, chorus, delay, etc... not too bad soundwise for a $39.00 pedal and a $129.00 amp. I like it better than my Zoom G2. I normally use it with my SS Roland 50-watter but when I tried it with my VJ I was surprised cause my Zoom didn't seem to like my Tube amps. Try a Korg with a VJ - you'd be shocked how nice they go together.
Now running an Eleven Rack with Pro Tools 10.3.3 - it's amazing and I'm having ball with it - worth every penny. PT 10 is tops IMO and the Eleven Rack is a work of art!