[Radek]

There are remarkable points in the posts of Imrahil and Dundee Slaytern.
What forced me to post my answer? We are seeing again and again the following picture: There are two groups of players. One of them - the good guys - are so called "role players". This group is completely different from the second group - the bad guys - called "power gamers". The posters FEAR that they are becoming power gamers and ask the others, whether they really have fallen so low that they have to count themselves to the worst that can be met among computer game players...
But it's different. Both concepts, "role player" and "power gamer" are rather nonsense. For example, everybody, who tries to improve his play style using his current knowledge about the game, is a "power gamer".
I think the problem is elsewehre. We can cheat and start the game with level 40 characters with 500 HPs and with +30 weapon in every hand available. Or, we can ignore the storyline and the classes and races chosen for the party and play the game as some hack'n'slash stupidity like Doom. But we can also play the game as a CRPG taking into account alignments, classes, races and the storyline. I think the last approach is the best and that it does not prevent anybody from searching optimal ways to victory. A paladin can behave as a paladin even if he knows which monster is waiting behind the corner. On the other hand, a paladin should never behave like an assassin.
Therefore, don't ask whether you are a "role player" or a "power gamer". You are both. Ask rather whether you are playing a CRPG.