Likewise. I have a Manfrotto 680B. Caution - they do not like sand. I wouldn't use it on a 7# lens - especially with a heavier pro body. I'd be more concerned with the monopod head, if you're not connecting directly. the original Manfrotto 234 monopod head had a very low weight rating - this head was mod'd & resold by Kirk as the MPA-1 (same weight rating, arca-swiss mount).
For a heavier rig, I use an Gitzo 5 series pod w/RRS MH-01 & same clamp as my ballhead.
For lighter rigs, I use a Sirui L-10 head on either the Sirui P-326 (a six section, great light pod!) or it's more pricey video relative, the P-426S. The Manfrotto is now pretty much back-up - after having a very bad beach shoot - where it became a hazard - although since repaired.
Note - I believe Sirui has since released a heavier L-20 monopod head.