If you want your IF ability compared to that of a Private Pilot with 40 odd hours under his belt, fair enough an IMC rating would do it
Actually, a PPL needs a minimum of 25 hours AFTER being granted his PPL. A big plus factor is that an IMC rating is only a minimum of 15 hours flying training, as opposed to 50(55 twin) for an full IR. And, it gives you the qualification to make VOR, NDB, DME and VDF approaches.
If, like me, all you want is to be able to get through bad weather into clear air at times, then it seems a viable(and much cheaper) alternative.