I have the i5 256GB/8GB model with discrete Nvidia GPU in the base (very handy for photography / light gaming). Haven't had issues with RAM although I rarely need to run VMs, and I have a SD adapter in the base to expand the storage for TV and films and so on.
The top model has an i7 and 512GB/16GB (same dGPU). It was about EUR1000 more if I recall correctly, not worth it to me.
Not sure about hardware refresh. I've seen rumours around that they might hold off for Intel's Kaby Lake parts which would mean 2017, but who knows.