The only time an MC of similar or equal caliber, success, and notoriety sends shots at another MC and that MC doesn’t respond, its because he’s scared of either two things
1). He’ll be physically harmed (Luda nor his camp was gonna physically touch muthafukkin T.I.)
2). He’ll get a lyrical smackdown that could damage his reputation and career
Fact is T.I. Ain’t want it with Luda, which using process of elimination means that Tip respected that Luda’s WRITING and BARS would give him problems.
I’d honestly say Luda as a writer is the equal of Tip. Luda just never chose to put an emphasis on “serious” or “street” music until the back half of his career, and when he DID get a little deeper with his subject matter, again, it was at least the equal of T.I’s from a WRITING perspective. Neither are in the running for the elite of lyrical MC’s.
There is actually video of TI running up on Luda back in the day and standing on stage while he's performing.