The Hammond SK2 Organ comes at a high price, it cost $2,890 bucks. It is the SK1 plus it has the extra keyboard with 61 keys attached which forms the SK2. The harmonic drawbars have 9 pitches and everything is very touch responsive. There are also a lot of effects on the SK2 Organ like Vibrato, Chorus, Overdrive, EQ, Reverb, Master EQ, and Multi Effects (and some more). There are over 100 patches (user) and over 100 preset patches.
Setting up the Hammond SK2 Organ is simple but using it could take some time if you have not used a Hammond before and especially one with two keyboards on it. You have two keyboards but only one interface that controls both of them so before you get into the live use of the SK2 I suggest you learn to change your sounds quickly and apply effects quickly too. Because the SK2 Organ has two keyboards it is a little heavier than a normal Hammond which makes it a little less portable to me. It still only weights about 40 pounds but once you put that into a keyboard case it could make it difficult to take it around with it (if you can find a case to fit it).
The SK2 Organ has MIDI in and MIDI out on it plus audio line out left and audio line out right. There is also an input for a foot switch or damper pedal. All of the sounds on the SK2 Organ sound really good and well designed. The feel of the keys are touch sensitive and have a nice weight to them. The on board effects are pretty solid for this style of dual keyboard.
The least favorite thing about the SK2 Organ has to be the price, but for what you are getting it is worth it for the live musician. My favorite part about the SK2 Organ is how good it sounds and how easy it is to change and navigate through your sounds.