current S&N employee here. As with any job, your boss makes it either successful, or an uphill grind. Marketing sucks in all S&N divisions so your boss has to be able to run interference to get things done. Be prepared to have a written game plan on how you will increase business, market share, and profit. All device / wound care positions are relationship based. Get the relationships, and you have the business.
I agree with those who say the company is a great place to start. Been making my numbers for a few years now and the offers come in every week. When the right one comes, I'm gone. Don't get me wrong, I really have enjoyed my years at Smith and Nephew. Good people and those in the other divisions in my territory are fun to be around. BUT, I can increase my take-home by $30-$50 g's simply by jumping ship.
Smith and Nephew one day will realize that they train the greatest salesforce, get them to create watertight relationships with doctors, hospitals and decision makers, then force them to leave by changing compensation plans and reducing takehome pay.