I just wondered if any members had upgraded from a Pioneer AX5 to an AX10? I have very recently been considering replacing my AX5i-S with the AX10ai-S, which I may have been able to get at a reasonable price secondhand. I decided to have a word with Pioneer themselves to see if there was any known issues with AX10, but was very surprised by the first comment of the Pioneer employee. He said that I almost certainly would not be able to hear any difference between the two models apart from the fact that the AX10 would go a little louder. This was down to their design being very similar. I would have thought that most manufacturers Customer Service employees would simply push the most expensive models, but not so in this case with Pioneer. He did say that the advantage with the Ax10 over the AX5 was the ability to drive lower impedance speakers better. Needless to say I didn't pursue this upgrade but I am curious as to what others have found. Has anyone upgraded along this path and found otherwise?