As others have suggested I think this depends on at least two things, probably more but I'll try to keep it from getting obscenely long. The frequency at which these tactics are used, and the opponents you are facing.
Since you used tactic instead of strategy I'll assume that we aren't playing these hands this way most of the time but instead doing it less often as an exploit in a situation that we think will yield good results.
As for the opponents part, against nittier, fit or fold players having more bluffs will generate more folds than they should and thus more profits. I think in general the strategy can win lots of small pots that add up quickly but when facing resistance can quickly cause us to lose a big pot. There may be some select spots where we can steal a big pot on a bad run out for our opponents likely holdings as well. Against these typically more fit/fold or MUBSy players this tactic will be more successful. Against the more aggressive or maniacal players, disguising the strength of our hand and letting them barrel off at the board will be the more lethal strategy as it will be more difficult to bluff these types of players.
As far as which tactic is more lethal, that is hard to quantify since they are largely player and situation dependent. In general it may be more likely that an aggressive player will continue to bet at a pot, making it grow, and potentially play for stacks more often. If we are bluffing, in order for our bluff to work we have to get the opponent to fold so we can't be playing for stacks. So given that the pots will be larger in the slow played hands and we are using these tactics at low frequency my best guess, all things being equal, is that slow playing a monster would be more profitable. But all things are never equal lol. This assumes we are equally successful in getting our bluffs through and folding our strong hands on bad boards. If we go to extremes however and hypothesize that Player A will always jam turn and Player B will always fold turn to a jam then it becomes more profitable to bluff since Player A will sometimes have a monster or get there on the river and Player B is folding everything except the nuts I guess (which is very hard to have). In real life people tend to make notice your slow play or your bluffs and slow down or make a stand eventually though.