I have a WHS 16 tb server. Works well. If the V2 means you are waiting for the new from M$ ...don't. It does not support drive pooling. Also from what I have read WHS and raid do not play well together...it does it's own version of raid..data duplication. It does work,,I have had drive failures and not lost any data. It is also a friendly piece of software. Install it and add the drives and walk away. There are also quite a few usefull 3rd party plugins for WHS, some free...some not. One nice feature is you can select which catagories are backed up. you might use the software folder as a temp file...so just do not check it and WHS will not back up the data. It saves you HD space. A word to the wise...take out the dust filters on your case and just blow out the case every (pick your time period). I had a dust filter plug up, which does not take very long and it toasted 3 1TB drives. You might want to increase the size of the os disk...all the data is written there first and moved to the storeage drives...but 250 GB might be allright also, not sure.
edit: crap, I just read the part about you allready having WHS V1...so you know this stuff...