I started my IMC just over a year after I got my PPL.
I think it was perhaps a bit too soon, but it did 'polish' my flying.
I don't use it much, to me it's more of a safety net, to provide extra navigation (I prefer it to using a GPS) and to improve my flying skills.
But I fly with an instructor now and again to keep myself in practice if I have to use it. However, one CFI I know thinks you should use it very regularly if you are going to use it at all.