About DR+IR - it is not possible right now, and there are no plans to do it. One reason is the lag that would be caused by transferring scene changes over the network. Another reason is that network rendering sometimes causes troubles, especially to inexperienced users, because of antiviruses, firewalls, and network hardware/software issues. So we prefer to have solid one-click local IR than complex network IR.
About IR speed - the best idea would be to download our 45-day demo and check how it behaves on specific hardware with specific scenes.
