big, heavy things that bolted to the frame and had heavy steel rods holding them off the wheel. As a result I hate them with a passion.
I dont think any of the modern SKS ones are really that heavy, and these CRUD ones have just replace the metal rod with plastic (which will prob break before the SKS ones) so not really that different. The main advantage with these, and the reason im going to get some, is they fit bikes without mounts and tight tolerances.
The real reason STW'ers need to buy them is cos MrCrud came on here a few months back asking for ideas/help so essentially they are a STW-derived product* (*not really but it'll sell a few im sure LOL!)