Absolutely. Apart from the added safety benefits if you're like me you'll enjoy flying on instruments. It's a different way of flying and has it's own rewards. Besides that, as I've said many times on here before one of the best moments in flying for me is ploughing through a crappy overcast and popping out into a fairyland of brilliant white cloud below you and azure blue above. It's worth the cost of doing it just for that.
However I stay current. I give myself a sixty day limit for approaches, if I haven't done one in that time I grab an instructor and go and shoot a few. Same with the IMC bit. Even if you have to go and search for some cloud to get on instruments with it's something you need to do.