It's not either/or, we can and look to have both.
Arshavin is our most productive wideman, our record signing and a flawed player of real footballing quality. Gervinho is more raw, younger and thus less proven but he has shown himself to be effective in the final third; he's not doing any worse than Arshavin did in Russia statistically. He's one of the top five players in France and has been integral to his team lifting their first league trophy in fifty odd years.
Of course that doesn't mean he is going to come here and tear up the premiership, he may not even get a game for all we know but If someone describes a player they want by saying "He'll also take some/most of the scoring burden off the oft injured VanPersie, and be another player the opposition defenders have to really worry about when we attack.", then I personally find it difficult to ignore this bloke's proven record.
