I only tolerate NTR like I tolerate my regular Hentai.
The only thing I hate is to be bored and to have the same shit happening over and over again. I also need a good artstyle to go with, of course.
At this point NTR tend to get in the "repetitive" category, at least for me. So I tend to avoid it because I know I'll be bored.
However, when it's played well I can enjoy the read.
The thing I dislike the most is having a beta guy looking at his girlfriend getting stuffed. This is something I've seen so much I consider it overdone.
Even if the whole hentai is good you only need to put this scene to ruin it for me.
Ok, this is fictive stuff and thus logic shouldn't count. But any normal person would have any reaction BUT that.
Even if the artstyle was not so great, I loved reading "Hole Family" because of it's fun story.
One NTR hentai by Jin was also fairly enjoyable, though that was pretty fucked up for me. At least we didn't get a cliché ending.
Only moment where I hate NTR is in parodies, I highly prefer not to have characters I like being put in NTR parodies. Especially if it is poorly made.
Final opinion: Like any other Hentai, only if played well and imaginative. And this doesn't mean you have to put tentacledicks, I'm talking about story.
On a final note, I wonder what is the appeal of NTR for Japanese, is it the same as ours or is it based on something different.
Reverse NTR when? that should be interesting to see.