To rack or not to rack, when bottling the home brew is the question,.

I have a question about racking off beer to mature in a secondary fermenter as I have seen this talked about a bit in various forums/books. I am currently BIAB and fermenting mostly ales at the moment (APA, AAA, Irish Red, Bitter) in the standard food grade HDPE, fermenters or 20 L cubes. The initial part of the ferment where the airlock bubbles away furiously is usually be done in 3 to 4 days. From what I have read it would appear that leaving the beer on the trub for up to 2 weeks should not really have any detrimental effect on the beer flavour. Is this correct?

I have seen talk of racking beer to a secondary fermenter and leaving for another couple of weeks to mature. I was just wondering if this would actually achieve much if I am just going to bottle the beer anyway?? Adding priming sugars to the beer in the bottle means there will be another fermentation going on in the bottle, which should be left for a few weeks to mature anyway. 

Transferring the beer to secondary (which will introduce oxygen) and then leaving the beer sitting in a HDPE secondary which is oxygen permeable would seem to expose my beer to a lot more oxidation than simply bottling from the primary after 2 weeks. Is there any reason I should be racking to secondary if I am just going to bottle? Is the maturation that goes on in a bottle that different to the maturation that would be happening in a secondary fermenter?