I saw this earlier... personally I'm not a big fan. Ghiaciuc was one of the worst starting centers in the league the past few years, and I could be wrong but he seems about equal to Niswanger.
ESPN Scouting Report:
Ghiaciuc is an intelligent pivot man with marginal size and strength. He is quick off the ball and competes to the whistle. His lack of power and bulk will always be a drawback, especially in the AFC North, which is loaded with powerful nose tackle types. He is an above-average athlete for the center position and shows natural knee bend. Ghiaciuc does a nice job blocking at the second level and getting downfield, where his athleticism stands out. He runs well and can change directions in space without looking awkward. His technique, blocking angles and feel for the game are all strengths to his game. He can recover when initially beaten. Ghiaciuc isn't a player to run behind in short-yardage situations and will not consistently blow his opponent off the ball. While he should continue to get stronger, he is incapable of out-muscling his opponent or pressing bigger defensive tackles off his body. He isn't a mauler and is more of a technician. He is inconsistent to anchor effectively versus interior power rushers and needs to increase his haunch power. Ghiaciuc is an okay starting pivot, but often needs help getting movement in the run game from his teammates and his lack of bulk and power will always hinder his effectiveness.