Like any tool get the appropriate tool for the job first, if you have extra money and want to spend it go ahead but don't think pedals or shoes are going to make you a pro.
I use SPD-SL because I never walk when I am on the bike, never in 2.5 years of riding. So for me using a more efficient system that SPD-SL provides is a no brainer. As for shoes if your feet are comfortable stick with what you have. I had problems with Shimano's got a pair of Sidi's and now I have no problems. I am on the bike 8hrs a week so being comfortable is what is important to me. I have no desire to upgrade to carbon pedals or soled shoes, no point.
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The problem with the gene pool is that there is no lifeguard and the shallow end is much too large
2013 Noah RS