We should indeed compare PyPy3.5 vs CPython 3.5.3, but having a benchmark suite that works on both continuous to be a problem.
Regarding 2.7.13 - you might find it surprising, but it's actually SLOWER than 2.7.2, there has been no speed improvements and quite a few speed decreases, so we decided to keep the faster one.
EDIT: part of the problem is that comparing PyPy 2 vs CPython 3 is apples vs oranges, but PyPy3 is not ready yet (unicode improvements I'm working on right now are missing)
I don't find it that surprising, but do find it disappointing that you would run benchmarks against the current version, but not post them online for perusal, nor provide any sort of explanation for the use of the older version in head-to-head comparisons. For me, at least, it produces the impression that PyPy has something to hide, and I doubt I'm the only one.
This is the usual case of budget - if I had budget to have anyone improve the website, improve the buildbot, improve the benchmark comparison, trust me I would do it. Right now there are no volunteers and the benchmark side is sort of lingering on.