Which 5 series engine is better

[Mr Green]

I've had a 520 with the 1991cc 24 valve engine and fancied moving up to 525 but now I've noticed that it's possible to buy a 520 with the newer 2171cc engine, I know the horse power difference is 22bhp but is the newer engine a better deal? Has anyone owned(or driven) both types?

170bhp is enough for me.