Hi folks... at the risk of being pounded for not searching previous threads .... (need a quick answer)...

Can anyone tell me what th difference is between the standard Iron pipes and the 2.5inch V&H pipes are?

I am about to get the V&H slips ons to replace the standards.... but how would this setup differ from a complete 2.2 inch V&H system?

Factory headers with a good set of slip one will outperform most v&h pipes in most cases. The exception is a 2-1 system. Only go aftermarket full exhaust if after a certain look or 2-1 system IMHO.

A full V&H system will probably weigh noticeably less than the stock setup. The stock crossover bracket thingy alone weighs a tonne.

My 2-1 is a feather weight in comparison.

Slap.

Am I serious?  Either do a search on previous posts on exhausts which are practically posted everyday or take the free advice for what it is. I don't reply to questions (that others don't care to answer) because I like wasting my time and making up stuff. If you don't like or believe the advice, im sure a shop will happily tell you that v&h exhausts are supreme and take your money. 

Not sure what model you have but I went from straight through slip ons (I bought my sporty second hand) to stock for the roady, the difference in acceleration was very noticeable (in favor of the stockies) then went to V&H short shots (mainly for sound and looks) and performance dropped slightly (running quiet baffles), then went back to stock headers and Screamin eagle slip ons and I am very happy.
You need some back pressure, however I must say I run stock a/c and no tuner but do run xieds.