The pic of the blue cocker has been flipped on the vertical. it appears that the ram and the lpr are on the wrong side. I conned LJ on MSN into thinking it was a cool upgrade that all our team are getting done, hence his previous (now edited) post sorry LJ!
Anyway, we'd better stop threadjacking...
On a minicocker, the front section of the body (volume chamber) is cut off. The screw that holds the semi block on acts like a volume chamber. This screw is about 15mm across and it's hollow with holes along it's length. A lot of gas is held inside the screw. In the past minicockers weren't as reliable as they had a much smaller screw, thus holding less gas, and often suffered from drop off as a result.
The pump rod and 3 way rod are shortened on the mini and the front bottle mount is on the bottom of the semi block.
A lot of ppl think that the bolt is shorter on the mini, but it's actually the same size.
Other than that they're about the same... except my mini is PINK