I have fired two (two of the three variations). They are a .32 auto, and that about says it all.
The problem is that the breechblock is held to the recoil spring rods by a pin that can be left out or not locked. If that is the case, the breechblock can come back in the shooter's face, resulting in something less than a fun day at the range. In spite of being the product of a prominent gun designer of the period (Andrew Fyrberg, who worked for I.J. for many years), it is not a good design.
A Google search will turn up a lot more info, and there is a good summary here:
http://www.triplek.com/Products/id/38/grp/412/prd/1381/
The Schwarzlose mentioned is an odd blowforward piistol; there were two variations, both imported by Davis-Warner. The Infallible was made, deliberately, with an outward appearance similar to the Schwarzlose, but the Infallible is a straight blowback, without the complexity of the blowforward design.
Jim