I've used several types of indicators, but my favorite is the Fish Pimp. The main reason why I don't always use a dry fly as an indicator is that with something like the Fish Pimp you can easily and quickly change the depth of the nymph. On some waters, that's critical. If you are fishing a stream, for example, and moving from hole to hole then it is a real drag to have to change your rigging every time the depth of the hole changes-- which could be every 5 minutes!
On the other hand, if the depth that you're trying to fish is consistent, and somewhat on the shallow side, then a dry/dropper is perfectly appropriate.
In the case of BBoat16, if the fish are striking the indicator then that's a sure sign that it's time to use a dry fly or terrestrial, with or without a nymph. And my money would be on "without a nymph".
Most if not all of the time you need to let the fish dictate what's on the end of your line. And if it's saying that it wants an indicator, then by God you should give it an indicator with a hook on it!
