Where are they taking BBC World Service?

Now that BBC World Service is moving back to broadcasting house at the top of Regent's Street, YouTube is starting to show us glimpses of the their new home. Skip through the exterior shots (first three minutes) to take a peek inside. Looks impressive, especially the use of daylight. Wonder it will sound like acoustically when everyone has moved it?  When I first looked at the plans I thought it might be like working inside the cone of a giant loudspeaker (complete with the whispering gallery effect that you get at St Paul's cathedral). But apparently that's not the case.