I used to run front freewheel on my first real trials bike, it was the old box-tubed onza t-pro. It had a cheap shimano freewheel on it. I never had any problems (apart from trousers getting caught in it!). I dont remember it skipping even once and I never tightened it. I wouldnt call it a reliable experience though as it was on a mod and I was just starting out, no big moves! I then ran a hope mono on the back when I got my first stock and it was good at first, but as I got better my experiences of the hub became worse and worse. I started needing new internals and eventually whole new hubs every few months, and there is no way I was a heavy rider. Just as it knackered again I found a chris king wheel on ebay and got a 36 spoke king classic laced to BMF rim for £150, good condition too. Since I got it my hub has skipped badly once, and thats because I put the wrong oil in it. I considered front freewheel to replace the hope hub, but I heard too many bad things about them so I decided on the king.