Don't think.. do !
Don't just think about the IMC, do it ! it is well worth the time and money and the experience. You've got to build hours anyway and what better way than getting an extra rating and in my opinion more relevant experience. The IMC will give you a good indication of how well you will be able to hack the instrument rating when it comes along and any areas where you need to read up on or do a little extra work.
Add to this the small bonus that it could save your life one dull day in the UK and it speaks for itself. Did mine last year and no regrets. used it twice since.