I've done what you're considering: I've left my husband for some horny messaging guy I met through the internet. Sex with my ex-husband was not good, I didn't like it. I'm also a three time abuse victim (lucky me... pffff), so sex will always be sort of a struggle for me. But this guy knew how to turn me on, where I thought that I was frigid he proved me wrong. So after a couple of months I left my then husband, got DF'd and in a couple of weeks I was living together with this oh so sexy guy...
And it turned out he wasn't that sexy after all. He was actually good in bed, but the rest of him was awful! He was rude, unkind, he lied, was looking for fights all the time, made me cry more in a year that I had cried in 15 years of marriage... so I was wrong! The only thing that was good about him was that he gave me the courage to leave my husband! I would've never felt strong enough to do that on my own. And even my ex-husband admits that if I hadn't left, he would have never done it. Not because our marriage was so good, but because of all the logical reasons: having two kids together, a mortgage, a business and a shared life for over a decade... But he thanked me years after our divorce for having the courage to go, 'cause he now knows we're both better off and even the kids say they are glad I did what I did.
But the guy I did it for.... it was a joke, really, nothing of real worth!
add: except for the text messages, I've been open and honest to my ex-husband. I never cheated on him, I had already left him when I had the first time sex with the other guy. And I promised my ex to tell him if I did, so he would be free to re-marry a nice sister (which I stupidly did and got DF'd for it, not knowing that within three months my ex would leave the JW's too!!! So after all it wasn't necessary for me to be DF'd after all, I could have faded if I wouldn't have been the pleaser to 'help my ex out'... My ex feels sorry for me now, I've lost everything but our kids because of this, and he went into the world, found him a nice young chick, started smoking cigars, had sex without being married, even let her move in with him, and married her a couple of years later and no JW ever gave a damn about what he did. The only advantage I had by being DF'd is that I knew instantly who were the people I could count on... the only one was my ex! I'm glad we're still friends).