I'd call it a potential lifesaver. I happen to use mine "in anger" quite a bit, and keep it up to snuff as far as my lousy skills will let me, and fly IFR in IMC fairly regularly. But even if you don't, you only need one unforecasted spell of bad weather while you are airborne...
I wouldn't be without one, and would recommend any UK-based PPL to do the rating. There is a mental attitude thing to beware of - it doesn't make you invincible - but used sensibly it is a good safety device.
My IMC renewal "checkride" and my biennial sign-off just happen to coincide, so it's really a "no extra expense" rating to keep up.
The FAA IR, now, that's a different story.