I think there`s nothing horrible playing with a walkthrough except of the case when you print it and do everything looking at it (especially non-boss combat tactics). It appeared that I played some games a long time after reading a solution so I didn`t need to think how to kill Painkiller bosses for example.
But knowing the way doesn`t give you an EDGE - even if you know the method you have to realize it yourself (I don`t think you ask your relatives to pass the hard place for you ?

) and depends on your skills in gaming. For example, beating Painkiller - BOOH last boss. It` s
your own challenge to survive long enough to kill Alastor with both your sacrifices and enemy attacks.
And I had some cases myself when I couldn`t find some switch for a long time and had to use a walkthrough.
Jam it back in, in the dark.