For an informal but descriptive list of the pros and cons of recumbants, follow this link:
http://www.bicyclinglife.com/Practic...FancyBikes.htm
Keep in mind that there are good recumbants and bad recumbants, just as there are good roadies and bad roadies. Once your muscles, etc. have adjusted to a good recumbant, you'll likely be able to sustain higher speeds and go longer distances than you are able to do on a roadie. On the other hand, there are also some terrible recumbants out there. I once rented a recumbant from a vendor in Milwaukee that was little more than a toy. (I think I've gone faster and longer on an upright with a flat tire than I was able to go on this toy recumbant.)