A lovely shot Jerry with nice tones to boot. Like your composition here too. I've tried shooting this jetty landscape, and it doesn't work too well. I have a 5D MKII and all I would say is, if your happy with what you've already got and it does the job, then why the need to change. I personally tend to go for image quality over anything else. 1D to me says Pro or as near as and if one day i'm good enough to warrant one, then it's the way forward. But the reality is, i've seen people on EPZ with better photos than I could ever hope for using a 40D. The 5D MKII has masses of potential in the right hands.
Not sure if that helps with your dilemma, but I hope it's of some use.