I think the IMC rating for serious IFR work is hopelessly inadequate.
However as IO540 says it is a wonderful privilege particularly for what it intends to deliver.
The golden keys for those who intend to use the privilege regularly is to absolutely understand that the greatest care needs to be taken with how you develop your skills and the necessity that you have an adequate aircraft on which to do this.
I reckon flying a solid IMC sector with an approach to minimum or close to in a SEP without an autopilot and single pilot is one of the most difficult things we do (of anything). Even in a well equipped aircraft without an autopilot or someone to help in the cockpit and assuming you are current there is little reserve left to deal with emergencies and little redundancy of equipment. Most importantly there is no way to regain visual references and therefore no way of releasing the pressure.
Here is the test before you take on that sort of flying. You have solid IMC and cannot descend below the base, you get an unplanned diversion because your destination unexpectedly drops below minimum, your auto pilot has failed (if you have one) and maybe so has the AI. Confident you will survive?