I installed signature series 18" square vinyl tile from Lowe's 2 weeks ago. It was on clearance for 1.53 per square foot so it's not like it was cheap stuff. I have installed enough laminate, ceramic and vinyl in my life that I think I qualify as a pretty darn good DIY in this area.
The tile didn't match up, no matter what, there was a 1/8 - 1/16 gap between the tiles in the middle of the tile. There was so much adhesive that it oozed out between the tiles. 2 weeks later, I just had to wipe the floor down again (third time) with adhesive remover to get the gummy black adhesive off between the tiles.
I know I should have quit when I laid the first few, but I was anxious to get the job done. The good news is that this floor would have needed one layer of vinyl before I put laminate over it anyway so it would be the same height as the adjoining room with laminate. I just wasn't planning on spending 1.53 per foot for vinyl that would be covered anyway.
Suzi