LinuxMCE (which I do believe is badly named, because it encompasses quite a bit more than that), has to be the central system, because it ISN'T your run of the mill media center. I am SICK and tired of all these people who jump over with their uber-custom setups and expect this system to magically encompass them all.
I am sorry about your issues with the PVR-150 card. I did not have them, nor did I have a problem with the WinTV PVR-USB2 tuner, or my HDHomeRun that I currently use to record my high-definition content. As more people use and contribute to these systems, these things will be ironed out.
But please understand, that this is a LARGE system, capable of much more than Windows MCE could ever dream of, it has a lot of moving parts, and a good number of those parts (plug and play devices over the network), require that it respond to DHCP address acknowledgements (as other means of actively probing for network devices have mixed results.), and since it's kludgy to realistically poll promiscuously for these things, it's not effective to have the DHCP server somewhere else.
If something else works better for you, use it. But I can tell you, that the system DOES work out of the box, as advertised, so please, calm down... it's still early in the game, there are tons of bugs, come help us fix them!