I own both the Techno and Hip Hop boards.
I thought that the Techno board was actually that Dance board (with a new name!). I was mildly shocked to find out it wasn't after spending $520.00 Australian and slotting it into my JV1080!!
The loops on this boards are absolute crap. But there are some great leads, pads and hits. As for the drum kits, I'll use those in my Korg Triton anyday. These are definetly nothing special IMHO.
Also the vocoded speech sounds are a valuable waste of PCM ROM!
The Hip Hop board is simply awesome. I wasn't expecting this to be sooo good. The loops are great and I even love the vocal hits! The grunginess of many of the patches is very appealling and this has some great drum kits to boot! I'd get this before the Techno board.
If you can track one down, get the dance board because this contains a sort of 'best of' of all dance styles. But really you'll have trouble finding one. Another alternative is to find the Roland MDC1 dance expansion module which has all the dance board sounds stuffed into a 1RU rack. I own one and am very happy with it.
If you must fill that last PCM slot, get the Hip Hop or Orchestal 11 board. Yes they are both totally different but you'll soon know which one to go for! All the best.