I bought mine from Thomann 3 years ago, and have been working perfectly since then. There's really not much to say about a mic splitter, other than it doesn't modify our input sound to the FOH.
In a live situation, we use it as an input splitter for our vocals, bass and guitar inputs (6 inputs overall). One signal from each input goes into our rack-based digital mixer for IEM purposes and the other one goes into the venues' stage box via an 8 channel group-cable.
The thing has been in a rack for 3 years, so it's firmly screwed in. I don't use any of the ground-lift switches, but they feel a little flimsy. All good though for this very cheap price. The XLR inputs and outputs hold up really good, although our whole rack system was designed so we don't have to pull out any cables from the output side of the splitter.
All in all, I would definitely buy it again, and probably will, so we can have a dedicated drum kit mic splitter as well for bigger shows.
Can't compare it to "bigger" brands, because this is the first mic splitter I've ever owned, so take my words with a grain of salt. :)