Large VDI deployment. 10gbps to access switching?

Looking for hands on experience with large scale VDI performance on 1gbps to access layer.

Datacenter would be solid (dual 25gbps for member servers, quad 40gb to core) for an environment to support several thousand concurrent sessions.

VMware blast says it would only need 150-200kbps per knowledge worker even with dual 1080p displays which my customer is using to say “hey we don’t need to upgrade to 10gbps down to access layer.”

Their aggregation isn’t bad (dual 10gbps to distro, dual 1gbps to 10-12 48port switches) but I have trust issues with VMware saying they don’t need much bandwidth.

Am I overly concerned? I understand that traffic patterns would rapidly change as only VDI display scrape goes to thin client where standard traffic would stay within the VDI environment.

Thanks everyone