I have the Worksaver with a Rhino auger. Apparently, the Worksaver augers are a bit flimsy, the dealer has had the flutes peel right off.  No matter what you get, you should probably have 3 or 4 inches taken out of the length so it doesn't drag on the ground.  The BX has a short inseam so to speak.  I just picked up an 18" tree auger as well, so I'll be giving that a try soon!
- Patrick W.