Should I study at the University of Arizona or Drexel?

For engineering. I've been accepted to both and want to know which one is better. I plan on transferring to UPENN (pending the admissions decision (I know a BIG pending..)); but I'm wondering what school would be easier for me to transfer out of to a school like UPENN. UPENN's undergraduate engineering curriculum attracts me more than the others. Also if you know.... how long do I have to transfer (and maintain good grades) at one of these Universities to be eligible for a transfer? For example, is one semester of perhaps a 3.7 or higher GPA enough to be considered as a transfer, or do I need more credit under my belt? I thank you in advance.