I just purchased this machine from the Army / Air Force Exchange and have had it in my home for just a few days now. I'm absolutely sure that the first review was submitted by a troll, because with out a doubt this is an excellent machine if you're interested in improving your lung capacity, strength, and endurance. I own a Vectra VX-38, AFG 7.1AT Treadmill, and a Free Motion Dual Cable Cross Trainer Commercial... the ProForm is of the same caliber and will give you the workout that you want, particularly for your stamina and the strength of your legs and core at a much faster rate... something my other machines can't provide. Cardio HIIT vs Treadmill... I'd pick the Cardio HIIT anytime... less impact and a whole lot more fun. My only suggestion is... if you're a walker, take your time with the Cardio HIIT to build yourself up, your first few days are bound to be a challenge. If you already have great lungs, strong legs (especially your "rectus femoris")... have at it.
I decided to buy this product because I was hoping that Proform would have worked out the issues with this machine, but I should have listened to the reviews regarding squeaking and poor customer service/support and stayed away. After only a few uses, the machine went from being basically silent to squeaking worse than an unoiled Tin Man running down the yellow brick road during a heatwave. I used the Proform website to submit a request for support (several times), and it's been a week and a half and I have not heard a peep from them- not a good sign. It's really disappointing to spend (waste?) so much money on a machine and then have problems right from the start, only to reach out to the manufacturer--who supposedly warrants the machine for several years--and realize that the warranty is worthless if the company never responds. The machine does provide an excellent workout, and that's even without going all the way up to the highest level (even level 12 of 24 is fairly rigorous). It is also pretty easy on my joints. But, the squeaking is so loud it makes me not want to use the machine; it's loud enough to interfere with watching television or listening to music. Also, the heart rate monitor is useless. I don't think I've seen it go above 100 BPM (and I know for sure my heart rate is way higher). My advice is to find another machine/manufacturer.