BH for me are usually painless tightening (but not everyone experiences them that way). In the days leading up to labor this time, my ctx were somewhere on the continuum between BH and "real" labor contractions. They were more attention getting, and I could feel them sort of pulling in my cervix. I don't remember much in my back.
With my oldest, my ctx were in my back in the weeks leading up to labor, and then in actual labor, they were totally in the front

and more menstrual crampy/tightening sensations. I think maybe DS was posterior and then shifted before actual labor started, because the ones in the weeks leading up to labor were more uncomfy than my ctx in active labor. It was obvious to me they were labor ctx though as I woke up, water broke, and contractions were immediately about 5 mins apart. we had a 40 minute drive to the hospital for his birth and it wasn't even bad. I remember encouraging DH to stop for drive through breakfast for himself as he hadn't eaten yet that morning and he gets shaky when he doesn't eat.
With my 2nd DC, my ctx were more the classic start in the back, wrap around to the front kind of contractions, and sort of general crampiness. But they were pretty painless for 95% of my labor. The only time they got really intense was on the way to the birth center in the car. Before and after, I wasn't even sure I was in active labor (other than them being in a regular pattern, they weren't overwhelmingly intense at all), and I was 10 cm dilated by the time I showed up to the birth center. Membranes were still intact so I hung out waiting to feel pushy.
This time around my contractions built up to something between BH and actual active labor contractions in the 2-3 days beforehand. Nothing crazy, but I could feel more pulling in my cervix and they seemed a little longer/stronger?. I woke up at 3 am (was fine all night before that) to what felt like one HUGE contraction...I swear it felt like it was 2 mins long. They were immediately about 2-3 mins apart, sometimes 4. But they were very strong (stronger than with my previous two.). I don't remember feeling them in my back though. DS was born about 5 hrs later.
I've had 3 different experiences. For me, the back thing was *not* really true. I've also been able to walk/talk through contractions with each of my labors up until the very, very, very end. After my experience with my first child, i've had to remind my other care providers that walking/talking through contractions is not a good gauge of where I am at.