If there's a sufficient chance that the car will be sold, the connectors that bolt in or weld in at their ends are easier to un-do.
The fully-welded type, not so much.
I've added them to a few cars, and noticed the increased rigidity even on the street.
I wouldn't add them to a mint original car, but in a case where the car's being raced, or where they're not too difficult to remove later, it's likely not a resale problem.
My restored RR has them, and I looked that over when I bought the car - which I then re-restored - and their presence didn't factor into my purchase.