We've used WPS 7.0 SP1 for several years now, never needed to upgrade to SP3.
But now we are moving to a new Windows 2008 R2 (64 bit) Virtual Machine.
We're thinking about upgrading our package environment.

How is the interface and stability compared to WPS 7.0.
Is it a better product, is it worth buying it?

I'm asking this because we are very happy with WPS 7.0.
We can do (almost) anything we need to with this product.

But when WPS 8.0 is at least as good as 7.0 we will upgrade ;-)