While I am a newbie and a lurker on this forum and a definite wannabe in terms of owning an SMB, I am a big grill/bbq user and have used one of the fire pans shown on Greg's post on numerous river trips to the tune of hundreds of days and have a few comments/observations:
1. They are really, really heavy.
2. They are really, really dirty. We keep ours in a canvas bag to keep all the ashes, grease and detritus off the other gear on the raft. It lives on the very bottom of the raft with the ammo cans piled on top of it.
3. The grill/grate gets really rusty and is hard to keep clean- I think it's just made of steel, not chrome.
4. They use a lot of charcoal.
5. It's hard to cook/sear meats rare because the lowest setting of the grill/grate is too high. We usually just plop the grill/grate right down on the coals when cooking steaks etc.
6. Works well as a fireplace- probably better than as a grill/bbg.
7. It's bullet-proof.
When (not if) we buy our first SMB, we will definitely be looking for another grill to use and will leave our river fire pan in the garage with the rafting gear.
For those of you that want to look at these fire pans, Cascade Outfitters in Boise has them and you can find them in most retail shops that sell river/rafting gear.