Have all of these separately, including the TV series, so no thanks. But it is a cheap way to get everything at once for those that didn't buy them all for $200 over the years...
And miss out on the ass-blasters? No, the first trilogy, and the prequel, are really good, have the most satisfying creature life cycle, and Burt Gummer is my hero!
Tremors (1990) is one of my favorite movies of all time. Tremors 2 is a worthy sequel especially for direct to video. Tremors 3 is flawed (especially the CGI) but fun. The rest either ehh or bad.