To make things quick, I've been using a fist-to-five approach. For example, ask testers, "How do you feel about the functional quality of the product after the work done in the last cycle? Give your evaluation on a scale of 1 to 5-5 meaning fantastic, 3 meaning so-so, 1 meaning not at all acceptable." Since most people have five fingers, this approach works pretty well. I ask the question, and then ask everyone to give his rating by raising a hand with some number of fingers up. When the team sees a disparity between different members, we know it's time for a conversation.
The last thing you might do to end your cycle's evaluation phase is a process retrospective or reflection session. This is where we look back at how fast we're moving, the quality of the product, and the general health of the team. Looking at all those things lets us answer the question "What will we try to do differently?" The answer to that question usually will be changes to the agile process—the specific ways we do things.
The retrospective is much more productive when done on the back of a healthy pace and product evaluation. If you're engaged in agile development, look closely at how you evaluative the results of your cycle. Do you look thoroughly at pace, product, and process? If not, you may not be getting the real benefit of short development cycles.