TR,
I think to answer your question as I understand it, the rear is more important to have right and by right I mean predictable first and plush second. I think the rear is much more important to "invest" in than the front. The rear is where most of your weight is so if it works well, less chance of a major get off and the rear is where you get your traction from, so a well working rear gives better hook up through and out of corners. Although it is uncomfortable to ride, I can get by much better with an average front end than an average back end and still keep up a good pace with an average front end. The right oil and a bit of air pressure to compensate for soft or saggy springs is a cheap way to compensate. Of all the bikes I owned the one I hated the most was the one with the rubbish back end. It kicked and bucked all over the place and sent me to hospital twice in a year. The best bike I ever owned had the most predictable rear end, maybe not the plushest, but the most predictable rear end, with OK forks and if you ask me that's where its at 'PREDICTABLE'. If I know what the rear end is going to do when I inevitably bite off more than I can chew, then I feel more comfortable getting closer to the edge and it is more fun too.
KJ