I am only familiar with the Kimpton and the IC - both this year.

The IC has the far better location for restaurants, shopping etc. There is Centralworld, Big C and a few others within a few minutes, often connected via pedestrian bridges and there is a BTS station direct in front, but it can be a bit noisy especially on the lower floors.
The Kimpton is the far better and nicer hotel (even after the IC renovation), but it is a bit isolated in a more green and more quiet area and it requires more walking, Taxi, Grab,,,,.
The IC has a club lounge, the Kimpton has not.
Breakfast at the Kimpton is far, far superior compared to the IC.