Broker price feeds

As fx is a de-centralised model, I presume that different brokers get their price feeds from different places. I was wondering: a) is there any consistency between the prices that brokers receive; and b) is there consistency between the prices we, as traders, receive from different brokers? Let’s, for example, say I was trading live accounts with two different brokers … I know prices wouldn’t be identical, but would they be close enough not to make a significant difference?

There must also be one or two high level entities which ‘control’ and synchronise the prices that are pushed out to the market … (I’m assuming this as there generally are in these sorts of models, but I don’t know for sure!)

I have read on a number of occasions that [I]some[/I] brokers manipulate the prices quoted to their customers for their own benefit … MT4 seems particularly prone to this, although I don’t see why this shouldn’t apply to proprietary platforms as well. Is there any truth in this and what could I do to ensure this doesn’t happen?

Any insights gratefully received … regards to all,
Dan

For most traders it makes no difference (most don’t use multi-venue strategies).

The price you are quoted is the price the deal is done at.

Other than for rogue spikes the standard amount of deviation I’ve seen is always less than 5 pips and even that could be attributed to latency in the broker feed.