Here’s a question I’d be keen to hear the answer to: how does the MXR deal with tuning when the string energy decays? Does the pitch drop as the note rings out when held for a long time? This is something that makes a huge difference. In the C4, you can hear the pitch drop off noticeably. The Future Impact handles this far better. The earlier version would cut off the note dead as soon as the unit detected pitch drop. The v4 is even better as there’s now a rolling buffer which stores the pitch value, so when the unit detects a small pitch drop in the string it takes the previous correct value from the buffer and holds that pitch for as long as the string continues to ring out. It’s an awesome feature, and allows the full release time of the ADSR to be used with rock-solid pitch throughout.