This list of scores is not 100% but it is generally accurate. I haven't checked the scores of your CPUs on it though.http://www.cpubenchmark.net/cpu_list.php
Off the top of my head I would think (worst to best sorry):
e5200 - worst
250 - best
In my experience, the athlon II/phenom II will perform the same as the core2 with the core 2 (these pentiums are core 2 based) at 200MHz slower. The cache of both processors is the same in the comparison above.
-I don't believe there is an advantage. If there is, it is very small.
-hypertransport is the link between the RAM and CPU. The hit on hypertransport will not make a difference.