Intercontinental is a weird hotel brand. It is so inconsistent from one location to the next that it's impossible to pin down what exactly the brand stands for and what one can reasonably expect when selecting an Intercontinental hotel.
Lizard Island offers a very unique experience to adventurous travellers who also enjoy a touch of luxury. The location, a private island on the edge of the Great Barrier Reef, is basically unbeatable with no direct competitors of any kind.
The Radisson Blu OSL is about as convenient as it gets without being physically inside the terminal. In fact, the Sofitel LHR is considerably further from its terminal, despite being technically inside it.
The OSL lounge can't be accessed via Priority Pass and I think this helps to keep the numbers down. The catering is decent, there are numerous seating options and the staff are also friendly and proactive in clearing glasses and restocking items.