I've gone through a number of low to middle-priced stovetop espresso makers since I started using them in 2004. Unfortunately, from my own experience at least, it's hard to predict which one will work well. The first I had which I bought in Spain worked great until the gasket wore out and the hand broke. I've never found one that worked so well, but I've managed.
This one appears to have the same design as others I've used, but for some reason is very slow to brew and sometimes requires that I hit it on the stove a bit. It's like the grind blocks the filter and prevents the brew from getting through or something. I'm learning to get the grind just right so this doesn't happen, and not to overpack it, but this is unfortunate because the best espresso is with finely ground coffee packed well in the basket... The first 1/3 or so that comes out is like true espresso, but the rest is like watered down coffee, the combination of which results in something akin to an Americano, if not a bit stronger.
Overally I've been able to make this work but am considering getting a second, more expensive one with the hopes it makes a better espresso without the unpredictability.