The rules they wanted to be in place are listed above in 3 bullets in the main article.
Yes, there was independence for delegates. The reason for the rules change is that Paul’s tactic apparently was correct. He COULD have delegates vote for their choice. It is the national election in which they were pledged.
The compromise is just that: a requirement to vote for whom pledged. I think in a primary campaign to nominate the best candidate that such a rule is very short-sighted. The whole point of a primary is to discover who the candidates are. If something comes out on one of them right at the end of the process, then delegates need not to be pledged but free to vote the best decision.
That’s a dangerous precedent as well. Say it was Palin or some real conservative that won the primary. Then comes to convention and then Romney pulls a coup and delegates go for him. You happy with that?