You're assuming that the OP wants to take daytrips on the Tokaido Shinkansen. If he wants to take daytrips to the North (which makes sense to me) then the others that you mentioned are better. If he's thinking of daytrips to Kyoto (which doesn't really make sense to me), then Strings is convenient ... but not IMHO a great location for five nights in Tokyo. If he's thinking of daytrips to the popular tourist sites in the region around Tokyo (e.g. Nikko, Hakone, Kamakura) then he doesn't want to be close to a Shinkansen station at all and all of this is a pointless discussion.

I don't get the impression that the OP has worked out what he wants to do during his "at least 5 nights in Tokyo". Or if he has, he's keeping his cards close to his chest and only gradually revealing his master plan.