Doesn't come close to imitating a DG and has serious QC issues. Wouldn't bother.
It's more akin to a magazine tap then a full drop-in replacement like the DG kits are. It doesn't solve the issues of undue sear wear on a GBBR that's not really designed to be shot full auto so regularly. Lots of stuff can break on the DG kits, but usually it's seals or a small metal part (generally the airshaft). On a GBBR-tap like this you will end up having to replace the hammer, sears, BCG etc. after a year or so (depending on usage) and that's not cheep if you're switching to steel.
Remember, DG kits are a huge lump of metal that replaces the bolt and trigger mechanism (except with the MG kits where it only replaces the bolt). They're rightly very expensive.
Ultimately it doesn't save any money and really doesn't have any intrinsic benefit over something like a GBBR mag tap other than not having to switch your line over. If you're looking for an affordable stop-gap then really your only choice is some CQB Russian-style taps.
One thing I will say though is don't buy a DG kit if you're not willing to give it some TLC for the first year or so. They are not easy to get working right immediately (even in some cases where they've been professionally fitted).