So I've tried 4 onaholes so far. As a starter, I got something cheap: My sister can't be this tight-Kirino, and My sister's friend can't be this tight-Ayase. I must say, they were disappointing. Too soft and not stimulating. I think I went over an hour with both of them.
I then decided to get something that was more stimulating. I bought Passionate Wife and Age series: Seventeen Bordeaux. They are both amazing. Stimulation wise, Passionate Wife wins by far. For fun, I like Seventeen Bordeaux more. I didn't expect either of them to be as stimulating and I ended up finishing much earlier than I had anticipated.
I tossed out my first 2 onaholes out immediately. I'm hoping that Passionate Wife and Bordeaux to last me couple of months with gentle care.
Now, I'm looking into onahole that is 'most realistic'. Pretty sure this is subjective for everyone but I'd definitely like to hear what everyone would recommend.
Age series: Seventeen Bordeaux: http://blog.onahole.eu/age-series-seventeen-bordeaux.html
Passionate Wife: http://www.toydemon.com/passionate-wife-masturbator