The BETA unit comes with 60 gigs. Final release systems will probably be more configurable, if you want to order one now with a bigger harddrive, you should call the store directly and talk to them about upgrading it.
StreetDeck is locked to the hardware. If you change the harddrive, you will have to call up and request a new registration code.
What warrany issues do you have? The hardware now comes with a 1 year warranty and the software should be fully supported after we take it out of BETA. All BETA units will get a free software upgrade to the final version.
The software has been locked down and hasn't had any major feature upgrades for the past 6 months while its been in internal testing. Our internal testing team is unable to crash it anymore, but we still expect a number of quirks to come out when releasing it on a global scale which is why its still in BETA.