Let me start by saying this ab machine delivers RESULTS. The first time I used it, I thought 'Oh this isn't so bad' - famous last words. By rep 15, my abs were screaming in ways I didn't know possible. That LCD monitor doesn't lie - you'll see progress fast if you stick with it.
The assembly was shockingly easy (and I'm someone who usually ends up with 'extra' screws). Had it ready in under 20 minutes while watching TV. The foldable design is genius - tucks right between my couch and wall when not in use.
Now the not-so-great: that knee cushion situation. I'm 5'10" with athletic thighs, and oof - after about 10 minutes, my knees start protesting. I've taken to folding a towel under them which helps. My petite friend tried it though and had zero complaints.
Unexpected bonus? It's become a family affair. My teenager uses it for core workouts, and even my mom (who hasn't exercised since the 90s) gave it a go. Just be warned - that 'burn sneaks up on you' as other reviewers said. Start slow unless you enjoy not being able to laugh without pain for three days.
For the price and space-saving design, I'd buy it again despite the knee issue (hence the 4 stars). Just maybe keep some ice packs handy for your first week.