Hi
firstly, welcome to Trucknet 
secondly, no need to shout 
all in capitals is classed as shouting
now, regarding the DAF, the main differences between the 430/480 adn the 530 is, the 530 has a bigger radiator as it tends to run a bit hotter, it also has a bigger turbo
i was running a 530 for 2 years with no real problems engine wise, it pulled like a train
i did have to replace the viscous fan coupling after it failed and threw the fan itself into the back of the radiator, luckily, it didn’t damage to rad too much
as with all DAF engines in the pre MX engine range, they had a problem with the head gaskets leaking after a while, which resulted in replacing the head gaskets and head bolts, the problem itself was caused by the sealant on the head bolts cracking and coolant getting past and knackering up the head gaskets
as for fuel economy, it all depends on the type of work you are doing and how hard you drive it, Comical Motor had a 530 Superspace on demo a while ago, they achieved approx 7.5 mpg, that was running at 44 tonne around their test route
the one i had, if i ran it flat out everywhere, and drove it with a heavy right boot, i was getting the same sort of figures, BUT, i reduced the speed from 56 to 52 and basically let the truck do the work, as in, use the cruise control where ever possible, and the retarder, and basically drove it more carefully, i was regularly achieving 9+ mpg, these figures were worked out using a pen, paper and calculator
i have seen a couple of these limited edition models with the beige interior, they are the same interior apart from the colour, they will probably have a better stereo system than standard too
personally, i didn’t like the colour, they can look quite shabby quite quickly if not kept clean