Saucony Men's ENDORPHIN PRO 2 Running Shoes (Open Box)

Let me start by saying that I have no other carbon-plated shoes to compare these to. I got into running a few months ago and I started off with the sauconey guide as a daily trainer. I ended up loving the guides, as they offered a lot of stability for my 200lb frame. I then started researching various running shoes and I read great things about these. I DO like the "bounce" and "roll" that the shoes give me, but it's very hard for me to get a snug fit on my shoe to where my foot doesn't feel like it's sliding around. And I'm quite certain I have the right size. It's also a very hard shoe that you wouldn't want to use as a daily trainer. These things are for speed...not much else. I've got a 10 mile race coming up and while I know these shoes are fast, I'm a little bit worried that my joints wont be able to take the beating. I'm debating whether to run the race in these or my guides. I will run 10 miles this week in these shoes to see how it feels.