I tryed the va-7 for two days next to my X1 and I can assure you that the X1 is far better than the va-7. First, the X1 is more practical for live performance, second it has a sampler and the styles are more realistic than the va-7. I tried the variphrase option in the va-7 and after one hour I get board of it, it is not a useful function as for example the sampler in the X1.

If you have the choice only between the va-7 and wk-8 then I tell you go for the va-7, but if you have the choice between the X1, va-7 and wk-8 then I strongly advise you to go for the X1.