Considering that the people doing the offering already own a controlling interest in DEP makes it pretty unlikely that there will be a lot of negotiation. Frankly I'm surprised they did the offer at such a high premium.
At the offer of .95 unit conversion (not 0.92), it's a good deal for DEP holders and a good deal for EPD (vs. them raising capital). Which DEP owner is going to turn down an offer for an instant 28% capital appreciation, PLUS a 25% increase in quarterly distribution, all rolled into a tax-free transaction for a security that is growing faster? I won't.