To me the IT is overall liberal-left inclined but not simplistically "left-wing". It has a fairly wide range of opinion - including from the other side Michael McDowell and, maybe, Stephen Collins. I hear people of a left wing persuasion complaining that the paper is "right wing" as they moan about something that one or both of these has written. Perhaps that goes to show is that what people find most memorable is what annoys them the most, be that the McDowells, etc - or the Mullallys, etc. Anyway where on the left/right spectrum would you place John McManus, Cliff Taylor, Newton Emerson?
Neither the IT or the Indo are as unbalanced as much as the UK press is, eg The Guardian, The Telegraph, The Mail.
Investigative journalism is expensive. The Irish Times no longer has the resources to do it
That is true - but then I am not sure that there ever was a golden age of investigative journalism in mainstream Irish daily newspapers. To the extent that there was it tended to be in periodicals like Magill. Maybe also in the early days of the Sunday Tribune. All long ago.
The IT tries to differentiate itself from the other newspapers by offering opinion.
They also have a range of interesting foreign correspondents (at least I find them so) - eg, Michael Jansen, Denis Staunton, Jack Power, David McNeill, Richard Pine, etc.
And they have Frank McNally!