Van Persie and Rooney are better, all accusations of bias aside sheer statistical evidence alone tells you that without doubt before you even get into the all round abilities of them i.e assists, set piece play, ability to play in other positions, technical astuteness, link up play etc, i genuinely dont think you can make a serious argument for Aguero and Tevez being a better strike partnership if your taking bias out of the equation completely which to be fair i understand is very difficult to do in this case, it would be interesting to do a poll on this taking out opinions of both City and United fans and asking the rest of the league as a whole who they think is the better or would fear facing more, it would probably give you a better idea and would certainly take any accusations of bias away.
Statistic wise though, Van Persie got 40 goals in all comps for Arsenal last season, that was easily better than anyone else, he got 30 in the league alone, again comfortably the best, Rooney then comes second with 36 in all comps and 27 in the league last season, neither Aguero nor Tevez have ever posted such numbers in the premier league as a partnership or otherwise, Van Persie and Rooney were the top 2 in the country last season and it looks like thats got every chance of continuing this time round to.
Not sure what this seasons stats are for the City pair but for Van Persie:
15 goals - 6 assists in all competitions
League stats:
12 goals 6 assists
Rooney:
8 goals 9 assists in total.
League stats
7 goals 9 assists
So as individuals RVP has contributed to 21 goals himself, Rooney 17, combined thats 23 goals/15 assists as a pair, 38 goals scored or created between the two.
Like i said earlier im not sure what the stats are for Aguero and Tevez so far this season im sure someone on here is privy to them but ill wager heavily they're not nearly as good.
Being a lesser partnership than Van Persie and Rooney is no slight on either Aguero or Tevez that point should be made very clear, they both very good players and clearly your best partnership, but a lesser partnership they are, they're just nowhere near as potent which to be fair is what some of you have already said before i get lynched for making that comment.