Any change in the recipe is going to change the flavor profile to some degree. Using a maltose-based source (DME or LME) is going to up the body slightly since yeast won't ferment 100% of it. Using simpler sugar (corn sugar, turbinado, candy sugar, honey, anything like that) is going to ferment out entirely, and can actually give the beer a lighter, drier flavor. It'll also have an effect on perception of the hop character. It ultimately depends on what you're going for.
Ultimately, the best route if you want a higher ABV brew is to go with a recipe designed with a higher ABV in mind.