i've always been a big fan of running leads as they are, imo, the most sensitive, indication wise and in the event of a breakage the lead is free to discharge. the only problem i have is when using them around snaggy areas or thick weed, when it would be an advantage to dump the lead. until recently the only effective way of doing this was by incorporating a rotten bottom, which can be a bit hit and miss and fiddly to tie, especially if your using pva tape/string in the damp. never been a fan of lead clips as i think the fish use the weight of the lead to discharge the hook. the only real positive with a lead clip is the ease with which the lead can be dumped. then i found something that is really cleaver.. using a modified lead clip that works like a running lead and in the event of a breakage, the only thing left behind is the hooklink. take a look at this link... be ready to be impressed. once you use one you will never use a normal lead clip again.
sorry, tried to find the vid of the lead clip system, this is of the inline system.