We do use reference kit, but also price-comparable kit (and often more kit as well to really find out how well a product can perform in different situations) so we both test a product to its extremes and with the kind of price-matched contempoaries it's likely to be paired with.
So, for example, a receiver will be tested both with our reference speakers and highest-end player but also, say, a Playstation 3 and a set of KEF eggs.
If it exhibits a particular sets of characteristics - say it's a bit bright, or, conversely, over-rich - we'll experiment pairing it with other partners, cables etc to see how we can get the very best from it.
And, of course, all the time this is being done in a comparative environment - each product we test is being compared to a best-in-class rival (and often ones below and above it in price, too) to put it in total context.
All this is something many of our rivals - who rely on freelance reviews where the reviewers simply don't have access to such a large selection of products to mix and match with - typically can't match.
More pictures and details of our reference kit here. Any other questions, ask away!
Clare Newsome is Editor-in-Chief of What Hi-fi? Sound and Vision