Yes, but many people could still walk away from love if the sex wasn't good or if other areas of a relationship are below standards. Love just like sex is important, but still only a component of a good relationship
Many guys can separate sex and love. Most often the sexual feelings arise before the love. Emotional connection usually takes a while to develop and many guys won't wait long for the love to come before sex. Most will wait a 1-3 months and will request sex regardless of where the love is. Waiting for love is unrealistic. Waiting a few months to build the foundation for a good relationship is what people should do if they want a long relationship in my opinion.
I think that it is very possible for both of these situations to occur. On a personal level, I could wait quite a while before having sex with someone, if I truly did love them (though I probably wouldn't want to).
For guys falling in love and having sex are fairly unrelated. Guys are willing to wait for a while (a few months to year) but you shouldn't expect a guy to give up commitment without being willing to give up sex. Ultimately a relationship is basically a transaction - sex for commitment.