I worked my way up slowly, with the instructor alongside me sometimes, till I'd happily take off into a 1200 foot overcast and route through the clag (below the icing) to wherever I was going.
That's not something I'd recommend without good preparation, but it's very satisfying to know that cloud along the way is no bar.
Inevitably, it led to frustration at not being able to use the rating abroad, so on to the FAA IR (achievable to anyone with an IMC rating and time to do the additional training). All I need now is the trusty group steed to move to the N-reg (this year, I hope).
The IMC rating is an excellent "taster", and a very useful rating in the UK. I'd recommend it to anyone who wants to tour the UK on a regular basis.