Once again, everyone has different taste. But for my money, Dutch and richoso1 have it right.
We all think low and slow when smoking. But, that is when we are thinking "Meat". That doesn't necessarily go for shrimp or prawns. For shrimp and prawns, you want to think low and short duration.
Next time you are ready to prepare shrimp or prawns, start ten minutes early. Don't trust me and what I am saying. Try this and decide for yourself. If this works, then you will be glad you tried it. If it doesn't, you have only wasted 10 minutes and 3-4 shrimp. And, you can always send me a "NastyGram".
Take just 3 or 4 shrimp or prawns. Put a large pat of butter in a frying pan, use a garlic press to squeeze in a clove or two of garlic. Mix it around and when it starts sizzeling drop in the shrimp or prawns. Those little 'bugs' will be turning pink in 30 to 45 seconds. Flip them over and give them another 45 seconds, "MAX". They are done!!!! Anything longer just makes them tough. I give this disclaimer on everything I say "everyone has different taste and different ideas", and I won't argue with any of you. But for my money, this is the way to do it. 99% of the people I know, even restaurants, overcook shrimp and prawns. We all love them and just don't know it is happening to us. Until you do it this way. Then you know the difference.
NOW, If I want them smoked I never smoke them until they are done and ready to eat. I use my age old method of "cold smoking", (which does not dook them) and then cooking like I just mentioned, above. If I am forced to hot smoke, once again I use as low of temprature and as short of time as possible. If you smoke them until "done and ready to eat", you may like them, but you will be settling for much less than you could be eating.
What do you have to loose? If you like them, do the rest that way. If you don't like them, you have only wasted ten minutes and 3-4 of the little 'bugs'.