The effects are shit cos it's an unfinished version, the CW always put an unfinished teaser clip up to whet peoples apetite. Thats why at 1 point it says "car comes flying at Clark".
As for doomsday, he's probaby gonna have some CGI added to him cos he looked better earlier in the season than that
mas, i think considering their budget, its the best they can do, to be honest its not too far off from the comic i think, not done a side by side comparison
the simple way to look at smallville, like they showed it in the comics, is that its one of the 52 earths in the multiverse, each universe is different, like one has the red son superman, one is our earth, one is superman as we know it in the comics, one is the golden age one with the justice society, one is the smallville one. i gave up hope on it being like the comics back in the 2nd season or so, if not earlier!!