As a former pipe smoker...........steve is right on. Tobacco is tobacco and whether it is destined for a pipe or cigar is all in the curing process.
True pipe tobacco (that is without casing, also known as flavoring) will have a true tobacco aroma. Most of the English/Scottish blends fall into this catagory. They can flavor the tobacco but only 5% casing, and it has to be a glycerin base, (so most of it evaporates), which by the way adds to the cost. If you can flavor the tobacco heavily you can maintain consistency from year to year. If you are prohibited from doing this you must use only the finest tobaccos each year to maintain your blend.
My post is running long, but the point is that most pipe tobacco aroma is not from the tobacco itself, but from the casing sauce (flavoring) that has been added to the tobacco. A cigar, for the most part, is from beginning to end pure tobacco. Sooo, unless you want to buy cigars that have been adulterated by flavoring, they are going to pretty much smell the same as pure pipe tobacco, other than the difference in the curing process.
Bottom line is; do you smoke for the aroma or the taste? If it is the aroma you want, then it really doesn't matter all that much what you smoke (pipe or tobacco), since you are going to be smelling whatever has been added to the tobacco to give it the aroma.
If you smoke for taste it makes a tremendous difference. You want the finest, purist, best constructed pipe or cigar tobacco you can find. However, you can't get away from how tobacco ACTUALLY smells. Some people are ok with it and some are not.
As for me, I smoke for the taste of it, regardless of what the aroma may be. Just my preference.