My opinion is based upon free pussy only. Furthermore, none of the Mexican chicks I've fucked spoke any english, so we are talking about a sample that hasn't been jaded by gringo culture. Also, because I am under 30, my target age is 18 - 34. I firmly believe that white american chicks over 40 are from a generation that knew how to treat a man right. These women are exluded from my sample, due to my youth. None of the white chicks I fucked were immigrants, so I assume that they are all representative of white american culture (the sample includes jewish, christian, and atheist chicks; as well as republicans and hard core liberals). Since I've had plenty of free pussy from white and mexican chicks, the following is my personal assessment:
1) White chicks do suck cock better than Mexican chicks. All the Mexican chicks I got for FREE didn't know how, or didn't do it right, or didn't want to do it. All the white chicks I got for free sucked it like its the last meal of their life.
2) Mexican women fuck better than white chicks, hands down. One sociocultural explanation I can think of is that Mexican men are macho, and they aren't educated (or don't care) when it comes to pleasing a woman. So a Mexican girl knows that once she has a man in bed, she better do what she needs to with him in order to make herself come. They grind their hips, ride you like crazy and put your hands where they need to go, all to get that pleasure before you come yourself. The further out into the countryside, the better they fuck. Period.
3) Going down on a white girl is more fun. Their pink pussy is more fun to eat, especially since white girls tend to take care of it by trimming or shaving, and deodorizing. Mexican ladies are mostly self-conscious about a man eating them out. Cajoling them into it takes time, and its not nearly as fun because they find it weird. Again these are unamericanized women with probably too much native american influence (most native american cultures consider oral sex taboo).
4) Kissing them is a tie. I personally prefer black women when it comes to kissing, because thicker lips make it more fun. Mexican and white chicks are about equal.
5) Yes, mexican women are much tighter, wetter, and hotter. For instance, the most "loose" mexican I ever fucked (for free) was a 34 year old mother of 4, who is an alcoholic (and obviously gets laid a lot in bars). Her pussy was tighter than all but one white girl I'd ever fucked. And she didn't look bad at all, in spite of her drinking habit and her birth experience...
6) Last but definitely not least... the Mexican chicks are far less money oriented than American white girls. You simply won't be able to bone an American chick without spending on her. In Mexico, I often get laid after splitting drinks 50/50 with the lady of my choice. In fact (perhaps in rebellion to the macho culture), they find you irresistable when you let them pay, or accept gifts from them.