As people have said, it is more down to what you want from a car. I have never driven a V6 so can't comment there, but love every minute I spend driving the DC5. I have driven quite a few cars, but this is by far the best driving experience. As someone said I think a V6 is more like one of those cars you just need to own before you die, I don't think it is a real drivers car but for looks and attention from other people there is little that will come close. But the DC5 also gets quite a bit of attention from people who are in the know about cars. I have seen people stop and take pictures etc of the car.
As for mpg I average about 28-30 doing mainly motorway driving (50 mile round trip a day to work). But thats also letting the car travel all of the way up to 8.5/9k revs daily. This is something that has to be done daily as detailed in the terms and conditions when buying a DC5
Servicing is not too much of an issue. I took mine to a specialist down south for my first service. It was a major service with new rear pads and it cost just over £200. Having just checked you are supposedly only 6.2 miles from System R who are another specialist and come highly recommended by other owners. I can't see how the parts thing will be an issue, unless you are going to be crashing regularly and need new panels. Most dealers or specialists have the majority of the parts readily available or can get them easy enough, a lot are shared with the EP3 any way.
My car is now standard apart from being lowered, but at one time was running about 260bhp by the previous owner. Good power gains can be had from not too much money. Something which is not the case for a 1*2 or V6.
As said, it all depends what you want from a car. A good driving experience (not that a V6 will be bad) from quite a good looking car. Or a better looking car that will draw the crowds but not be quite as good / fun to drive. Don't get me wrong, I am a big fan of the V6 and was considering getting one myself. But I do not regret my decision one bit!