yikes, a stranger from Virginia asking me about my Johnson?
Seriously, though, I really like it. It is, to be fair, a modeller, so there is something missing from it, but it is very versatile, has some good models in it, and if you are patient you can tweak some really nice sounds out of it.
How accurate are the models? I really couldn't tell you, but from what I hear, you won't pull the wool over anyone's eyes trying to pretend that you have a real Vox AC30 or Blackface Twin, but it will give you some good sound, some really nice tone, and if you have a tube pre to use upfront on it, you can really fatten up the tone.
If you get one, you have to use the J-edit software feature: it gives you a lot of options for editing (plus making it easier) than you can get justby pressing buttons. A foot controller is pretty much essential to have any real-time control over effects.
It has great effects in it, I often use it with amp and cabinet modelling off and plug into it and into either my fender or vox amp, and just use it as an effects unit. The flange/chorus is great, delays are nice, great reverb, and a sweet compressor.
For the approx $150 they go for these days, it is a great tool in the arsenal, especially for laying in tracks late at night.
I plug a y-cable into my guitar, one end goes into the J, one goes through my mixer straight to the soundcard to record a clean signal from the guitar. From the J I record via the S/PDIF out, and from the analog outs at the same time: in the end I have 3 tracks recorded in Sonar : a clean direct line from the guitar, the digital out from the J, and the analog out from the J (or two analog outs if I am using stereo effects). I find the digital out to be a little to "crisp", and the analog out to be a little too muddy, mix them together and it sounds better. And if I don't like the amp/cab/effects, I just take the clean direct track and run it back through the J and try out different patches.
very handy.