There's a certain amount of vested interest here Neil, as you make your living in DVD-A production and don't sound too keen on the cost of tooling-up for BD; it's always a good time to buy when you talk to the estate agent!
I've tried and tried with DVD-A, and I give up -- it's fundamentally-compromised as a format in its ties to the DVD-V architecture. I have access to DW Chrome and SurCode for home authoring, but the vast majority of players are just unusable in navigational terms. I don't know about you, but I don't want or need a TV turned on when I listen to music, yet there is no single player that I have found that will let me do simple things like enter random play or numerical track select without a blisteringly-confusing macro of button pushes, e.g., to play track 92 on my JVC EX-A1 I have to press '10' nine times, then '2', then 'Enter'. A CD player would ask only that you press '9' followed by '2'. Ditto random play on the Pioneer DV-610, where I must press 'Play Mode', then two clicks of the 'down arrow' to select 'Random', followed by the same cycle to select between 'Random Group' 'Random Track' or 'Random from all Groups'. Believe it or not, I have to go through the same laborious routine to select 'Random Off'. A CD player just requires that you press 'Random'. Try doing all that without a TV display. This is the problem: the fcked-up interface, and that's why DVD-A is dead. Let's not even go into the DVD-A track limit -- significant with redbook files, many hundred of which can fit on an MLP'd DVD-A, and the dreaded PUOs (Prevent User Operations, that we all know and hate from DVD-V [I once saw a DVD-A disc that said Forward Search was 'not allowed'!!]). SACD is hamstrung by digital-out limitations, as well as not being accessible to PCs, and is similarly finished. Like it or not, BD is the better alternative. Contrast all this with BD:
from the Pure audio site: "...Blu-ray combines the requisite storage capacity for surround and high resolution sound (24Bit/192kHz) with the uncomplicated handling of a standard compact disc (CD). This Blu-ray disc is configured in such a way that it can be played back with the simple functionality of a CD on any Blu-ray player. The user can, but is not obliged to, take advantage of the visual options (screen menu). In other words, the Pure Audio Blu-ray Disc is an autonomous medium: no TV is required to use it. The functionality is as easy as with CD: the user can navigate with the remote control and push the dedicated buttons for PLAY, STOP, SKIP and all other functions. The numeric keys directly access the corresponding track number and the desired audio stream can be selected by the coloured keys on the remote control. For example, press the red button for 5.1 DTS HD Master or yellow for 2.0 LPCM". All with no track limits and bags of space.
DVD-A had everything going for it and they screwed it up. Good riddance.