The Unitrree Pump Pro provides smooth, easy-to-change resistance in an easy-to-use, well-made, relatively inexpensive device. It's also compact, lightweight and looks cool.I think it's great as a supplement to, or replacement for, elastic bands if you prefer resistance you can set precisely and that can remain constant throughout the entire range of motion (rather than starting out low at the beginning and getting higher as you stretch the band). Like bands, you can also use it while traveling. It's also good as a stop-gap if you would like a full-fledged magnetic-resistance functional trainer like Tonal or Vitruvian but are waiting for the next generation of products with lower prices when competition increases.I use the device primarily for rehab/prehab upper-body exercises like external shoulder rotations, shoulder raises and wood chops that are somewhat awkward to do with free weights. It also works well for curls and other exercises that don't require more than its 44 lb. of resistance. I'm very impressed at how well it works for these. However, it's not a replacement for a room-full of free weights (I still use those) or a functional trainer. If that's what you expect, you may be disappointed.The key feature for me is quality of resistance. The resistance is quite smooth though not quite as smooth as a Tonal, as I recall from doing a demo on the Tonal more than a year ago. It's constant resistance (with a few modes that change that) like Tonal or other magnetic-resistance machines and doesn't have the inertial acceleration of free weights. I prefer the feel of free weights but have gotten used to constant resistance and find it very effective at increasing strength. Constant resistance also provides more resistance than free weights due to the lack of inertia, so 44 lbs. on this device feels like more than 44 lbs. of resistance from free weights (presumably due to more time under tension at full resistance).The device makes a whirring sound when the pull-strap moves in an out, similar to some rowing machines. It's not particularly loud and doesn't block out music or TV sound, but I find that it detracts a bit from the exercise experience, though not enough to be a show-stopper. The other thing I found slightly annoying was that you have this somewhat heavy 1.5 lb. device hanging from a strap while you exercise. It doesn't impair functionality but, like the whirring sound, I think it does detract a bit from the exercise experience. It would be nice if there was a cage that allowed you to mount it firmly on a power rack or wall without the use of an anchor strap.A second key feature is ease of use. The device is very easy to use. It turns on with either a double press of the on button or a quick pull of the handle. It requires a phone app to change weight and access other controls. I would have preferred the controls to be on the device itself or on a dedicated remote control. However, the iPhone app was easy to set up, pair to the device, and use. Changing weight requires waking your phone (if it's gone to sleep) and moving a slider--a few seconds including the time to get to your phone if it's not next to you while you're exercising.The quality of the device and accessories is outstanding. The device itself feels solid and looks like it was designed in a high-end design studio. The thought that went into design details and functionality is particularly impressive. You can anchor the device with a door anchor or loop anchor that fits over a pole or peg or chair leg (both included) or a suction cup (not included). They all attach using a twist-on rod that's quick and easy to use and much neater than a D-ring and carabiner. The included 30mm (1.2 inch) diameter silicone-wrapped ribbed handle with nylon straps is the best strap-type handle I've used apart from knurled steel ones.I won't detail all the thoughtful design choices that went into the device but I'll give one small, surprising and impressive example. When I first got the device I went to charge it and noticed that it had a USB-C to USB-C charging cable. My usual charger for miscellaneous devices like this is a USB-A charger, so I started trying to remember where I had left the USB-C to USB-C charger for my iPad. Then I looked at the cable more closely and noticed that it was actually a USB-C to USB-A cord to which they had thoughtfully added a USB-A to USB-C adapter. Think about how many times you have used products where the manufacturer put thought into a little detail like that that when it wasn't a selling point and would only make the user's life easier. They actually spent money to do that instead of cutting corners by reducing quality or features to reduce manufacturing costs.