Zachary, from what I've seen the products are new or significant upgrades. The primary objective of the Roadtest is constructive feedback from engineers and hobbyists. The roadtesters are only given a couple of months to complete the reports so that's not really long enough to beta test unless you were using it full time.
There's one Roadtest I was involved in where we realised after some of the reports were submitted that the products shipped were not the production models. Element14 recalled the products and the correct items well be resent.
