As she wasn't submitting any scientific findings based on her sexual encounters I don't feel that a larger pool of subjects was required. In fact, in this case, maintaining a group with fairly similar traits probably allowed her to make more accurate judgements. You're talking about a lot of guys that drink the same way, eat the same way, work the same way and act the same way. That she ended up with such varying results is actually pretty awesome.
And, I'm not going to agree with slutty or even having issues. I'm fairly certain everyone evaluates their partners before and after sex, she just did it on a spreadsheet. Would most people do that? Probably not. Would most people shake their titties while sitting in a tub of non-newtonian fluid for hundreds of eager wankers? Probably not, so who am I to judge? Just because she did something that I wouldn't have doesn't make her slutty or weird it just means she approached sex a little more scientifically than most of us do. Hell, I'd be more inclined to call her a slut if she didn't have such detailed accounts of her partners. A slut fucks and can't remember, a scientist fucks and categorizes.