I am biassed because I've had one.
530d all the way. Why? because you can get it in a manual version.
The 530d will feel quicker than the 535 (although it isn't) as the turbo boosts up at revs, it sounds better as the engine gives off a nice growl when pushed - the 535's twin turbo's mute it too much. No town work means you won't crave for an Auto.
If you are looking at pre-LCi 530d, get one with the updated engine. Look for the push button start - they are the later type. LCi's run a little better on runflats. Pre-LCi's are godawful on RFT's, get one on proper tyres and a spare wheel (there is a wheel well in the boot).
Ensure that the swirl flaps have been thrown away and the engine breather is "vortex" type (as the E9x's are) rather than "loo roll" type. 98% of 530's & 535's should have been changed by now. Air filter changes on a 530 are quite a long job, and they do tend to collect dead leaves. 535's are a lot easier.
A 5er will roll more than the 3, but it is still a nice handling car, and you can hustle it along at an indecent rate.
Expect mid to high 30's fuel consumption, over 40 if you drive carefully