It's an interesting point about the Data Logger.
I loved it in GT3, I would spend hours watching my NSX shimmy over the curbs around Complex String in slow-motion. But the one in GT5 is "boring" and doesn't allow the dynamic scrolling through the data, visualised in real time, or slow-mo, and scales on both axes aren't as adjustable either. But that's OK, because it's just meant to be a tool, right? Shame that information isn't exactly forthcoming from its "minimal" design, though...
I think someone at PD took the lessons in
The Visual Display of Quantitative Information to heart. I read it whilst I was working on research projects a few years ago, and I was tempted (for a "laugh") to present my results in figures inspired by the most minimal examples from that book to the department; but I never actually mustered the courage, given it would only (severely) enrage those who were used to actually being able to read exact information from charts, as opposed to just being able to gauge roughly what the relationship was (or just being given a number).
In other words, it's a lot of work to actually extract
numbers from the data logger; much as it is with the gear ratio chart (oddly enough, GT1
gave you those numbers i.e. max speed in all gears etc.; which is, of course, a waste of "ink", when the same data is in the graph... somewhere.

).