Mithch, I currently own a Modwright sony 5400. I owned the stock unit for about 10 months before sending it for the upgrade so it was well burned in and well known to me. The difference after modding was nothing short of amazing. I still love the 5400 and plan on keeping it. I haven't had the pleasure of auditioning an Oppo 105 ModWright, but by all accounts, it is an extraordinary piece. Dan is currently releasing a new DAC, his build from the ground up. I see no reason to think he would release an upgrade package for the HAPZ1 if it were not at least the equal of his current units.
I will do all I can to get a good feel for what the stock unit sounds like, but I only have a couple of weeks to work with. Dan has a $500 discount until the end of April. so there is a timeline here.
It would take more time than I will have to permit burn in and thorough assessment of the stock unit. The modded unit will probably require a couple hundred hours of burn in when it comes back. I will do what I can, but an unequivocal comparison would require a real time A/B.
Czar, I'm not normally an early adapter. I like to hear what others have to say before making this kind of investment. I am also eager to hear others opinions on a fully burned in stock unit. In this case, I am pushing things a bit to take advantage of the discount.