I got my upgraded MA3i last Friday and let it burn in for 96 hours, which is what the dealer recommended. By the way, Rick Brown of Hi-Fi One handled the upgrade and he was great. He took care of everything, kept me up to date, and coordinated with the factory to keep the turnaround time short. Great service.
I’m very pleased I upgraded. The noise floor is lower. I can hear quiet passages, such as during a Mahler symphony, more clearly. Micro dynamics are better. It’s easier to hear subtle slight changes in volume. Tone and timbre is better. Instruments sound more like the real thing. Horns have more brass, nylon strings more nylon, etc.
I can’t hear any downside to these improvements. The new i doesn’t sound brighter, hi-fi, or analytical. It’s still smooth. There’s less fatigue because the music is more intelligible. I noticed and categorized the improvements over the first few days, now I don’t focus on them much. If you like the character of the original MA3 and want it to sound a bit closer to the real thing, I highly recommend it.