spikey - 8:51 pm on Feb 27, 2007 (gmt 0)
Last last year I made a mistake in one of my automated scipts and broke my Search Submit feed.
I didn't notice it until a month or so later when I realized that all my "Inktomi" traffic was gone (I'd tagged the links ages ago before they were acquired by Yahoo).
Lo and behold, my Yahoo SERPs had acquired nearly as much traffic as I'd lost. AFAIK, Search Submit does nothing for your ranks, it just guarantees the breath and frequency of your crawl. If you're already getting good crawls I don't think this will help you at all. If you aren't getting good crawls then I think there are cheaper and more encompassing solutions.
With that small error I saved myself over $1K/month (Search Submit Pro charges a PPC fee on top of the PFI).