Well, hello Guidocorona,
Looking at the innards of the 302, it doesn't appear to be an analog power supply. I have heard, on good authority, it is not. However, I will graciously accept correction.
http://www.jeffrowland.com/model302reviewHFR2002pg2.htm
I am a former owner of the Pass Labs X600. Compared to the innards of the H2O, I'd say the H2O's power supply more resembles the Pass Labs analog power supply.
http://69.10.206.123/community/Photo.aspx?album=Henry%20Ho's%20H2O&photo=H20%20S250%20Inside%20A
There is also the matter of cost. The very best H2O, M250 Signature mono blocks (2 larger amps) cost $5500 (not pictured), whereas the single Rowland is three times more costly.