It very much depends what you use the HS2 for. If you use it to archive stuff off of the Sky+ then it makes sense to keep it downstairs! If you dont, then you could use it upstairs as an hard disk recorder ala sky+ but youd have to watch the recordings upstairs or use a videosender!
I'm sure it can (play back -R) but that get's expensive if you only want to watch it once! If you use Ram disks they'll only play on very few players at the moment. You'd probably need to buy a Panny S35 or S75.
you can watch as many times as you like, I think he meant if you only want to watch it once you use up and DVD-R which can not be re-used (hence will become costly even at £1.5 a time), unlike DVD-RAM which can be written and read many times (100k times is'nt it?)
But as he has the HS2 with its built in hard drive,he need not waste time with any RAM discs.
If you do not intend to archive anything its HS2 and Sky+ up and downstairs.
If you want to archive,use Sky+ for its recording convenience,then transfer to HS2 to edit out ads if required,then onto -R for keeps.