I completed an IMC rating, and used it fairly aggressively for a while. Probably becuase I was then very low in experience, the worries did not intrude too much, but the limitations (UK airspace only, no class A) were sometimes inconvenient, and when I got a posting abroad, proved a substantial hurdle - hence I went for an IR.
The studies have already been useful on several occasions (separate occasions of blocked static & pitot, travelling further & gyro precession, weather (no 214/215 abroad!) international law & border crossing etc. etc). In any case, these are i) the cheap side of the rating, and ii) can be fitted into 'spare' time with the exception of the week consolidation and exam (you're gonna need a fortnight off work)
The flying training is hard, but works more on the procedural side of the flying - my instructor told me it is considered a professional rating - and as such the examiner expects to see a professional approach. Also bear in mind that with this rating, you are becoming qualified to share airspace with commercial traffic.
Finally, I use it to fly airways when they are low enough (but without a turbo the choice is limited), and certainly for airways crossing, where the rating saves me a 4000' descent and climb on one of my more frequent routes.