Yes, there is a big difference.  The difference is that the two previous popes were caught in the fallacy that the "clearly defined teachings" can evolve; they are not static in many cases.  Otherwise, we can pick apart all kinds of things that the church taught that are absolutely wrong, and in some cases, people paid the price with their lives.  Ordination and homosexual orientation are two prime examples of what should...and needs to change based on scriptural exegesis and modern science.  The previous popes were clearly afraid of scientific advancement and hence"dug their heels in" and said things like "as it always has been."  Clearly not true in many instances and it leaves little room for the Holy Spirit to continue to allow us to grow in knowledge, even as we know that scripture is ever revealing.