I've been hauling the butt decoy aroundfor a few years now. I use it because I do backpack hunts and am always concerned with weight first. I like it, but in a less weight-conscious situation I'd probably take the side view.

In my experience, the biggest trick is getting elk to see the darned thing. If you do a lot of moving while you're working a bull, you may not get a lot of practical use out of a decoy. I constantly find myself with a bull near, needing to do a thousand things at once - get under cover, no that spot over there looks better, scurry over, nock an arrow, start thinking about ranges to various landmarks, etc.- and often never get the decoy out of the pack. I've had exactly two elk ever see my decoy in 5 years, oddly both on the same day. The second one was a nice 6x6 that is now hanging in my living room.

Hope that helps.