silverpeak have a massive established customer base for sdwan,...

silverpeak have a massive established customer base for sdwan, and a huge presence in the US government, and fortune 100 companies.

The product offering is much stronger and more advanced than others such as Cisco's acquired viptela product, and on par with Versa Networks.

in saying that, silverpeak, and HPE both, are targeted at large scale, large enterprise. You won't be seeing $1/user/month licence from these boys. It's a premium, known quantity product, with a massive support base and infrastructure behind them.