IMHO, Tailpipes clutter the rear view of the car. I'm a pretty "clean" guy when it comes to my cars so the less clutter the better. I'm sure its louder than having tailpipes, but I really don't know for sure because I had my H-Pipe welded shut at the same time the dumps were put on which quietened the car down A LOT, but it gave more of a "feel" to the exhaust (You can sorta feel the rumble echoing off the ground sometimes). My tailpipes were never at the same angle, and to have them straight and look nice, my mufflers hung too low and scraped stuff so I put turndowns on so I could shove my mufflers up out of the way but I love the look without it so it will stay that way forever.
If I was you, put your new mufflers on and put on dumps. If you like them, good. If not, they're only like $8 from Oreillys. Buy your tailpipes and throw them on and get rid of the dumps.