Here are my thoughts, based on 2 brews of each sample on separate days:
2003 Zi Yin (Nannuo)
Excellent aroma (Xiang Wei 香味) but what makes this a winner is the Hui Gan 回甘 which is long, deep, refined and powerful (and remains on the body for the longest time out of all the samples). In addition, the sweetness (Tian Wei 甜味) tells me that I will have many more enjoyable sessions to come.
This one has the best qi of the lot. Definitely old tree. But it loses out to the Zi Yin in terms of Xiang Wei 香味 and Tian Wei 甜味 as it is less complex. So it is No. 2.
Very impressive Xiang Wei 香味 in the empty glass pitcher (gong dao bei), and the source material is certainly quality (rich smell of malt and camphor) with good aging potential. Only loses out to the above teas because of less Hui Gan and Cha Qi 茶气. However, if I were to tong, this would be my choice (cheaper than the above 2). Tea soup is dark caramel. I also note that the leaves were personally selected by Zhou Yu.
2003 Mengsong (Qing Teng)
Amazing complexity, good aroma and Hui Gan (although 2/3 less than the Zi Yin). Its major flaw is it starts to turn sour from the 5th brew onwards and then its downhill from there. Wham, bam, then disappears - I have no interest in seeing it again.
2003 Zi Pin (Yiwu)
Although the Zi Pin has very good complex aroma (Xiang Wei 香味), its main flaws are:
(a) it has lingering bitterness (Ku Wei 苦味) which stays on the tongue, especially when you brew it strongly. A good yiwu should not have this quality;
(b) volatility from brew to brew (i.e. doesn't know where it wants to go); and
(c) the qi energy (Cha Qi 茶气) is off (i.e. doesn't grab you and ground you on the spot). Not something I would want to make friends with. Like a Changtai.