About time we had a proper topic for this one. Well just to let you know, I have a DTL-H30001 E and it cannot play the HDD Utility disc. Therefore it cannot install the HDD compatible browser software. I tried using a copied disc patched as a "master" and it won't play that either, you get the PlayStation2 logo but then the screen goes black and that's it.
Well, although the console may not recognise the HDD utility disc etc it can still use it (the official one).
I have Final Fantasy X International which has a neat feature that allows you to install the game to an official HDD so that the loading times are reduced. Well, I plugged in an official HDD that I had used in DTL-H50001 (currently it is matched to that with BB Navigator installed on it!) and to my surprise I was still given the option to install the game on the title screen. Normally if an HDD is used in another PS2 you need to format it with the utility disc in THAT console so it can use it.
Anyway, I installed the game and I can now play FFX on the DTL-H30001 - even though it cannot run the HDD disc. Also, the HDD does not spin at first boot-up (classic sign that the PS2 cannot use the official HDD).
If I use a normal 80Gb HDD, you are not given the option to install the game, despite it spinning up and reading it during the loading of FFX International.
Anyway - just in case nobody has ever tried this before, thought I'd mention it.