Wow. I think you just lost most of us. Yes, tastes vary. Yes, an older property would cost more to run and that's a perfectly valid reason to prefer a modern property. But using words like "horrible" and "monstrosity", and saying what you half acknowledge others will like "would need to be gutted" to make it "any kind of decent" is going out of your way to pick a fight.
Personally, I didn't mind the style of the house you're considering. I prefer it to the cookie cutter pastiche-vernacular houses developers too often put up.
The accommodation on the ground floor seems a bit limited, though. You get one room plus a "study/family room". The "hideous" house has two proper reception rooms as well as the open plan kitchen/diner/family room. The hideous house has a large plot and a good sized garage and outbuilding, whereas the developers of the modern one have stolen a big chunk of living space to pack a garage onto a plot that, though apparently a reasonable size compared to some newbuilds, has too narrow a frontage.
The layout of the hideous house looks decent for modern living - it has a downstairs cloakroom, utility, en suite facilities aplenty. It might need a bit of decorating, but not much more. Well, unless you want to improve the insulation etc. dramatically, in which case yes: you could spend a lot of money to achieve anything worthwhile....
Buy the house that suits you, and good luck! Or don't buy anything, keep renting in the UK and enriching a landlord. Or move back to the States. Whatever.
The UK isn't the only place where you have to compromise when choosing between properties, though. I've never made any significant purchasing decision - car, house, whatever - without having to trade off one factor with another. Hell, I'm trying to book a holiday now, and I'm torn between the hotel with the best service and restaurants, the one with a fantastic pool and waterpark, and the one where the room size and layout is best by a mile. Life is full of compromises.