Alright, yes I think it probably does answer my question, thanks for the extra info.
We have just recently finished evaluating some other cloud services as possible options for replacing locally-hosted testing, with the goals being to remove the need for local maintenance / administration of test hardware and allow resources to grow and shrink dynamically to suit current needs, and also to allow our various teams, which are spread around the world, to cooperate / share the same resources easily.
Ultimately, however, it was decided that currently the major cloud services aren't very well suited to testing a 'heavy' desktop application like ours. The cloud is doing well for server / service hosting, data / database, and then on the virtual client side, edging into web, mobile, and lightweight virtual desktops, where what we really need is virtual workstations. Also, having an external host to allow global resource sharing would trade one set of problems for another, likely just as thorny, given our current tools and workflows.
Still, I'm definitely keeping an eye out for any new developments in that space in case something comes along that would work well for us. It's cool that SmartBear is starting to build out integrated support for it, but I don't think CBT for example is going to be directly useful for my particular team. The general direction, though, is encouraging.