A full size M&P 9 will serve you great and you will have no regrets. As others have posted, the M&P is just a more refined gun. The SDVE series are great guns. I can't say I've shot one, but from what I've read, it is a great gun for the price. So really you can't go wrong with either.
Look at it this way, Its like buying a new car. You can get the base model that is stripped down and not much to it, or you can go up a notch and get a model that is a little more refined. ( In the M&P / SDVE case it would actually be a lot more refined!

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If you are absolutely new to guns, it might be worth finding a range/retailer where you can rent guns or hold them at the counter. Get them in your hands and compare the two. Good luck finding both at the same time at the same place!
IMHO when buying your first gun or any gun there are two major factors (other than knowing the type of gun you want) and they are 1st- ergonomics to YOUR hand and 2nd- one that is reliable/reputable. Find the model that fits you best. Your experience into the sport will be much better. For example, when I bought my first handgun, I got a beretta 92fs. I am a big beretta shotgun fan, so I figured I'd stick with the brand. Boy was I wrong! The gun is great. It just wasn't great for me. Plain and simple, I don't have big fat Oger hands to hold one of those.
If it were me, and price was not an issue, I would buy the M&P no question. I think you'll find yourself outgrow the SDVE quickly. I am very happy with my M&P.
If were to buy an SDVE, I would do it for merely having another gun at hand for a friend to shoot when going to the range etc.