Looked into these quite a bit just wondered what people's thoughts were, I know the mpg is very poor and a warranty is a must but wanted to heat first hand experiences?

Didn't have an 'M', but had the E60 535d, but was under manufacturers warranty so I didn't worry about throngs to be honest.
Great cars, shape looks a little dated in my view now though.
A friend had the V10 M and it was a beast. ON THE WAY: BMW F21 M140i
MERCEDES GL350 - Metallic Navy Blue w/Grey interior

GOING: BMW F31 335D MSport+ xDrive Touring
GONE: Land Rover Discovery 4 HSE - Stornaway Grey w/Black Interior (wish we'd kept it )
GONE: BMW F10 520D MSport - Carbon Black
GONE:MY12 RRS SDV6 HSE Sumatra/Ivory/Grand Black Privacy glass

i was going to get one off these but my mate who is servise maneger at bmw put me off with service and running costs so i got a 535 d instead

Running costs not too much of an issue as I'm away alot with business so car would be used 2/4 times a wk, wouldn't touch one without warranty.

I got the 535d m sport instead then got a remap to 345bhp and still got 40 plus mpg on motorway (sticking to speed limits tho )

No use to your question but the bmw diesels are really good even better when taken to evolve for tweaking.

The E60 is a great car. M-Sport kit and 19" spider wheels make sure it still looks fresh today.

535d would be my weapon of choice. LCFC. Receiver of threatening letters from Overfinch.

I've wanted one for years but can't help but think it's a terrible idea whilst I am trying to save money  Current: 06 RR Sport HSE TDV6, Bonatti grey, black leather. Defender 90 pick up. Vito 110cdi

Previous: Mercedes CLS, BMW 330cd M sport, Nissan 200sx, Impreza STi, EP3 Civic Type R

I test drove a couple before buying the RRS, It's a seriously quick car!! Just the servicing costs kind of put me off! BMW warranty is £1k a year i think and then something like £2.5k a year after a certain millage(70k?) Basically everything was £1000.......Discs and pads £1000, service £1000, clutch £1000 etc etc! Oh and god forbid you have gearbox problems!
Quite a few around now but some with quite high millage and the shape and interior does feel quite dated now.
That said its still a M car and would be amazing to own! Would always put a smile on your face, One i test drove had some kind of BMW approved aftermarket exhaust and sounded amazing!

Two mates have run them and both went through 2 gearboxes. Soon as cars were out of warranty they got shot. Amazing car to drive and be in, in full M mode they are brutal but also brutal on the gearboxes. The gear change in M mode used to make me cringe, it's like a kick in the back followed with a horrible thud into gear and then off you go again. 2007 TDV6 HSE