Darrin Mourer writes about his experiences and learning as a sales engineer on his blog. I personally have found some of his posts well written and interesting (read this for instance).
He does also talk about the use of Virtual Labs in the sales engineering process. It is a three part post that was written a while ago. You can read the posts here.
From his blog, here is what is written about virtual labs:
With everyone having access to the same virtual environment, SEs can use this as a launch platform for creating enhanced demos that would not be doable with a laptop. SEs should be able to share these demos with others. Having a standard demo catalog with the best of the best content is a great way to drive additional revenue. SE management/enablement and marketing can also leverage the work that SEs create and incorporate them into the master library. If you really want to get fancy, you can start tracking this in your CRM to statistically determine which demos work better than others. This is all part of building a repeatable sales process.
Some companies use evaluation and proof of concept interchangeably. Sometimes a customer just wants to kick the tires without an SE. Sometimes the customer needs to see the product in action to validate the technical specs and sales presentation. Allowing SEs to build a environment that matches the specific requirement of the customer can be a huge time saver for both sides. It also reduces risk to the opportunity be being able to run the POC in a controlled and familiar environment.
One other very valuable use of this type of platform is as a training aid. Instead of trying to get access to a classroom with a purpose-built set up, or messing around with virtual machines on laptops, you can configure the labs ahead of time, virtually, and allow students to access them through the browser on their laptops. Whereas the demo and proof of concept provide additional revenue opportunity, this is an easy way to demonstrate cost savings to the company.
Virtual Lab Automation Blog 