#73 nice clean design but the tracks adjacent to the 'L' limit the space for the
company name underneath and causes the logo to appear unbalanced.
#70, I don't feel this conveys the message that we work with printed circuit board design and logic systems, it appears scientific but again the text below should be on one line.
#71, I believe this is the best of the three, high impact, would look good on a webpage, good colour scheme and the company name is on one line - I like it