It all depends on advocate to advovate, their knowledge, sincerity and loyality. If advocate is genuine and sincere any fee pattern is ok. Befor engaging any advocate we must do extensive research, to get the best counsel for the case. If some one wants to win the case, fee is not the only crieteria. If by paying huge fee, win is guranteed then then manu sharma and sajeev nanda would have won the case.
For client point of we should go with part payment or datewise payment, in this case we can keep check on the activity of our lawyer, also if something goes wrong we can change the counsel. This also ensure regular visit and keep an eye on the progress of the case.
Worst is one time payment, where lawyers get unmotivated, if something goes wrong then they may say that do not worry we will file appeal, and we lost due to uncompetent judge.
One advantage with this profession is that clent prefer to keep the same advocate even in appeal also after losing the suit. Whereas we change the other professional on the failure.