We usually stay at the IC Strings when in Tokyo as we fly in and out of NRT and the proximity to Shinagawa station in combination with direct link via NEX is very convenient. We also need Shinkansen access and local JR so location is perfect for our purposes. On top our company got a good corp rate for King Deluxe rooms in the low 20ies with breakfast included so it works out well.

We stayed at all the other ICs too, IC ANA, Tokyo Bay and even Yokohama and none are as convenient as the Strings for quick and direct access to most of public transport options. Rooms are more compact for sure amd views less inspiring than say Tokyo Bay, but it really depends on your plans for your time in Tokyo and where you need to be / want to go. Also the Strings tends to be the most expensive on cash rates and offers the smallest rooms for redemption.

If you are worried about the Sgl Bed, 1 Person comment, all I can say is that I got a Double Bed room assigned on my last stay 2 weeks ago on a points booking. However, upfront I highlighted to them that a Single Bed would be a violation of IHG Rewards redemption rules which specifies Double Bed or King Bed to be provided.

I was told that the single bed supposedly is 1.4m wide, but can't verify it. Ask if unsure, they do respond within reasonable time. YMMV.

For points redemptions, IC ANA offers larger rooms and the airport limousine bus stops at the hotel which is also convenient. Location is in the midst of a livelier area (Roppongi) and access to trains is a bit of a walk, but nothing bad or very far.