I assume you're now hour-building, prior to CPL/IR, right? In which case, you need to fly a certain number of hours in order to meet the minimum requirements for CPL issue. Since you have to fly those hours, you may as well learn as much as you can whilst doing so - and the IMC rating is a brilliant way of doing that (as well as letting you hour-build with more ease since you won't be so restricted by weather).
On the other hand, if you've finished your hour-building, and you're now in a position where you could either start an IR course straight away, or do an IMC course followed by an IR course, then I'd suggest that the IMC probably doesn't have any real benefit.
So I guess I agree with the other posters so far, but with a caveat that it's only useful because you have to build up your hours in any case.
FFF
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