Personally I never really pay much attention to magazine reviews - tbh I don't really trust them (no offence intended <img src="/ubbthreads/images/graemlins/smile.gif" alt="" /> )...
I tend to wait for player reviews and then just pay attention to the negative or neutral ones (as the positives are usually written by big fans of the dev studio and would praise any piece of software they put out regardless of quality). The negative reviews tend to exagerate every little flaw but they give you a good idea of what the problems are and the neutrals tend to be fairly balanced in their opinions.
Still, having said that there are many games I buy on the day of release based on previous experience and Beyond Divinity will be one of them <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />
While I agree that magazine reviewers do not necessarily have to complete a game (and I appreciate that most would not have the time anyway) to get a good feel for the game, it can often be the case that the best content is front loaded and the later parts of a game can seem rushed (perhaps for this very reason). Neverwinter Nights springs to mind as one of these (including the expansions) where Acts 1 & 2 where fairly long and involved and then the later acts where very linear and tended to be very short (though generally the writing was better in the later acts).
I shall be taking my advice a little more seriously myself in future though after having been burnt on both the PC versions of Halo and Deus Ex: Invisible War - the latter being a complete travesty of a game when compared to the original.