I just broke back into the cheap wireless flash trigger world with the purchase of a kit identical but under a different brand to this four pack. I've had a few days to try them out, and the experience has been illuminating in regard to the relative advantages of Nikon AWS compared to really cheap radio for me.
The primary reason I decided to buy the triggers was to more economically expand beyond two wireless flashes and for that purpose, you can't argue with 23€ for a four pack. I already own non-wireless capable flashes, and it's gratifying to get them back in action. I was in minutes shooting with three flashes and the full manual experience, while fraught with trial and error, didn't take as long to adapt to as I thought. However, a couple sessions made it clear that a shortcoming of a totally dumb flash trigger is that the flash goes into sleep mode and the next time you take a shot, the flash wakes up but doesn't fire.
Upon loading them into the computer, more problems emerged.
Long story short, cheapie radio triggers can have a slight firing delay. In many circumstances this isn't an issue, unless you're trying to shoot at max flash sync speed like I was, at which point you can get a bit of shutter blackout at the edge of the frame. I found I got the problem at 1/250th but it mostly disappeared at 1/200th. Was not totally consistent even at the same shutter speed. A little googling turned up the suggestion of changing channels, which I did and I found one channel that seemed to nearly eliminate the blackout at 1/250th.
All that said, for 23€ I'm happy with what I got despite losing a number of shots to the learning process. I now have the option to field four wireless flashes for a very minimal investment, but I think I shall be switching between radio and Nikon AWS.
My experience with Nikon AWS was mostly pretty good, save for some failures to trigger (mostly my SB600) and a lot of exposure inconsistency and just plain underexposure when I bounced the flashes. The later was really the bigger problem, but I realized (slightly late) that there's nothing to stop me from shutting off iTTL and just manually adjusting flash power from the camera. I did that for the first time today, and found that since I was free of the sleeping flash problem, it was a much more suitable setup for chasing my kids around.
In conclusion, cheap radio triggers are a very good budget option for the budding photographer who wants to primarily do studio-type work, but it has serious shortcomings for candid photography. I don't know if higher end radio triggers are free of these issues.