Is it a bad idea to leave the "chain" attached, tie up with with twine, and roast?

I've always removed, but thought leaving it would just yeild more meat.

I roast, then move and leave on a cutting board for folks to cut and serve themselves.

Here's what we did (I used to work in the meat industry in the portion cut area)...

The top notch, white table cloth restaurants would tell us to always remove the chain.

The restaurants that were more concerned with cost per unit told us to leave it on.

Personally, I'd remove it.

You can use the chain to make a kick ass cheesesteak sandwich.

Yeah, I'm aware of the myriad things I can use the chain for. I just can't seem to find a good reason to remove it.

My wife's hosting a party tonight for a bunch of chicks, so I thought leaving it on wouldn't hurt anything and would just yield more meat.

If I tie it up really well, I can't imagine any of these broads would even notice/care, etc.

My father in law always leaves his on. I asked him why. He said, "there is always someone who will only eat meat that is cooked to medium-well or well done. It's for them."

The side chain can have a thick strip of connective tissue that runs down the length of it and it's sort of hidden between the chain and the main muscle.

For roasting whole, it's probably fine to leave on.

If I was cutting and grilling steaks, I would probably take it off. Also, depending on how it is trimmed the side chain piece can be hard to keep attached to the main steak. In my experience, the little side piece winds up dangling off the steak and doesn't make for as nice of a presentation.
ToddyHill is spot on.

i removed it, but may leave it on one of these times for science.

Remove it and toss it in a hot pan with butter.