I have used power block and bow flex and I think these are excellent values compared to them.
Pros:
Price, better per lbs
Shape, flat bottom allows better resting on legs
Faster dialing in: all adjustment done on top, not ends or sides
Cons:
Weight: doesn’t have the ability to expand in weight
Intuitiveness: there are 4 weight adjustment, need to read the instructions to know exactly what to adjust for what weight
No weight is perfect but for the price, the negatives matter much less for the average users.

The NordicTrack adjustable dumbbells are a real winner that are working out well for my wife and I.
Pros:
1) Nice weight range (10-55) and sufficient increments for me. We have a small set of 2.5 to 8-lb individual dumbbells to fill in on the very low end.
2) Compact dumbbells. The dumbbells are no longer than needed for the weight you are using. The 10-lb configuration is narrower than the 20-lb, which is narrower than the 30-lb, which is narrower than the 40-lb, which is narrower than the 50-lb. DO NOT DISCOUNT this when shopping for adjustable dumbbells. You do not want to be swinging around a 2-ft long bar in each hand when simply using a 10-lb dumbbell. It gets in the way and limits the range of motion for some exercises. These incrementally add plates to the end as the weight goes up. So they are compact at low weights, and very much the size of a fixed dumbbell of similar weight at heavier weights.
3) Easy to adjust. The adjustment system is low effort, but locks solidly and seems unlikely to fail long term, normal use.
4) Value. Not the cheapest, but give a great bang for the buck.
Cons:
1) Slower to adjust, relatively. Some changes require moving 4-adjustment levers on each dumbbell, depending on what weight you are switching between. A single or double dial is quicker, no doubt. But, note that I said "relatively". They really only take a couple of seconds to adjust, and it has been a non factor in my workouts.
2) Missing some weight choices. You can add 2.5-lb or 5-lb to the coarse 10-lb, 20-lb, 30-lb, 40-lb, 50-lb settings. So you can do 12.5-lb & 15-lb, but not 17.5-lb, etc. The next increment after 15-lb is 20-lb. You could fudge around this by selecting an uneven amount to each end of the dumbbell, which would make them unbalanced by 2.5-lbs and give you a 7.5-lb increment. But I don't suggest doing that. For me, the increments are fine enough for what I do, and I move up and down in 5-lb amounts anyway.
3) maybe more fragile than fixed weights? This is actually a comment that applies to probably all adjustable dumbbells, simply because they have a selection mechanism added to them. These do not appear fragile in the absolute sense, but I have no plans to drop them the way you see some guys do with fixed weights at the gym.
I researched buying these quite a bit, and narrowed it down to several contenders. The Bowflex dumbbells were one finalist, and are undeniably slick, with the one-knob adjustment system. But, they (and some others) have a disqualifying flaw (in my opinion) where the dumbbell bar is always full length, regardless of how much weight you've selected. Even at whatever their minimum is, you are swinging around like a two-foot rod with each arm.
Anyway, I'm a happy customer, and these are working great.
5/2/2025 UPDATE: 15-months later, and these are still going strong and doing the job. One annoyance is the lack of labels indicating which way to move the 2.5-lb/5-lb levers. But I solved that by putting a small dab of silver automobile touchup paint on the 5-lb side (SEE photo). Seems like an obvious issue that the manufacturer would address, but it only took a couple of minutes for me to fix it permanently.

So much quicker to change weights, real game changer. Great quality.

I looked long and hard for a high quality adjustable dumbbell that would feel like one in the gym. I watched many online reviews and read a lot of articles. This one checks a few boxes for me, but has a few downsides.
Pros
– compact: it is much more compact than something like the bowflex
– quick change: only takes a couple of seconds to change the weight
– flat ends: no issues putting these on your knees when getting set up
– pretty low cost all things considered.
Cons
– weight selection mechanism on one of them doesn't like to engage the small 2.5 or 5 lb weight. I've had these fall out on me once I picked them up.
– cradle: have to be careful dropping the weights back in. They can get out of alignment and it's not obvious how to get it right 100% of the time
– max weight: at 55 lb, these are good enough for some lifts, but I've maxed them out for others. However, I knew that going in.
– these don't really seem that sturdy. They're holding up so far. I've used them probably 20 times, but the amount of plastic and kind of wobblyness of them doesn't inspire confidence.
In the end, I compromised getting these because of their cost and the design. I'm happy about that. I can live with the cons so long as they continue to hold out. Something like a Nuobell may last longer, Ironmaster be super durable, or powerblock heavy and fast, but they also have tradeoffs and are much more expensive.

This was the 3rd pair I purchased and am happy and relieved that they arrived intact. The packaging was excellent and protected the product very well (pics 1-5) I am convinced that the first set I bought around 4.5 weeks ago was a returned/damaged/defective set (pics 6/7). It arrived completely destroyed and missing pcs. The second set was lost by UPS.
I will say that Amazon Customer Service was excellent to deal with. They refunded me in credit within an hour of speaking with them the first time which I used to purchase the second pair. The second time they just issued a replacement order.
Onto the item:
The dumbbells themselves are very solid.
When I first unpacked them and moved the sliders I did experience a little bit of stiffness and jamming on one of them but after sliding the selector back and forth a few times I haven’t had any more issues.
They are easy to use and I can change weights much faster that unspinning a color adding/removing weight etc. I chose these over similar models for two major reasons:
1) you can increase weight by as little as 2.5 lbs. most of the other brands are 5 and 10lb. increments.
2) the weights are a reasonable size at their lowest weight and get bigger/longer as you add weight unlike some brands like the Bowflex that are super long despite not having the additional plates.
For these reasons I was willing to pay more money.
I also looked at SMRTFT Nuobell but they were $250 more for the 50lb model and $450 more for the 80lb model which both adjusted in 5lb increments. So in my opinion this set was the better value.
I have only used once (today) but I already love them