After being in a similar position recently i.e. torn between all four mentioned brands , I narrowed my search down to the Trek Madone or a Wilier. It came down to these 2 mainly due to local stocking and I wanted a bike I could sit on and try.
The Trek 5.2 was a fantastic bike but the shop I tried it at wouldn't even put pedals on it for me to sit on the bike and try for comfort reach etc. so I ruled them out instantly. The bike looked great is all that I can say. I've heard a few people are having problems with the BB on these bikes, don't know if it's been fixed yet.
When I went to try the Wilier the shop put pedals on it and let me try it out. I ride a 54 specialized frame but a medium izoard was to cramped so they got a large for me, perfect fit. Just try them out for size before you buy.
The finish on the frame is A1 with a good clearcoat all over the frame and no missed bits or less coat on the undersides which other manufacturers seem to be doing!! The frame itself is a featherweight as are the forks and have a strong carbon weave with no squeezable bits anywhere . All of the campag and other finishing kit is also spot on with the exception of the Rubino pro tyres which I find give a hard ride and are skittish in the wet taking fast bends. They have been changed to my usual gp4000s.
The ride is firm but not harsh and the frame has no flex, it responds to every turn of the pedals instantly. The weight of the bike and it's responsiveness gives instant acceleration. Considering the stiffness of this bike it is definitely not uncomfortable but it definitely feels like a race orientated bike and not something like the comfort based specialized Roubaix. I have a problem when I get on because I can't ride it slowly, it has to be ridden fast. It climbs better than any bike I've had and descends perfectly now the tyres have been changed ( so far 49.7 mph in the dark ). It gives you the confidence to keep off the brakes because it turns in and holds a line with no problem and has no wobble.
I also forgot to mention that it looks amazing just standing still and they aren't as common as a Trek, Bianchi or Colnago ............
yet
Highly recommended and must be added to your shortlist to try out. Their ( Wilier ) customer service is also 100%. They've replied to all of emails so far and are extremely polite unlike UK companies
Saluti
Dave