I have a TET mod on my 22-250 and although it is well made and does an OK job I will never have another.
I couldn't strip it after firing about 100 rounds and still can't now, it is totally seized inside and even after soaking in water overnight it still wont budge.
Even worse than that is the fact that it is just not as quiet as it should be, it is on an approximate Mark 1 ear-hole par with my Hardy mod but is nearly double the weight.
I am big fan of the DM80 mods, I have had 3 now and all have been good, they are not the dearest either.