-Felt AR FRD. With EE's, Quarq and the new Mavic Pro clinchers (all carbon version that are now sold and I'm too lazy to look up their full name) it was right at 6.7kg. This was the bike I always said I'd buy if I left Specialized and made good on that by buying it within weeks of leaving. It sucked. And I wanted SO bad to like it. But it sucked. The under BB brake and flexy BB made it so I had to open the brake super wide so it wouldn't rub on even mild out of the saddle efforts. Add to that a fork that was also super flexy and it made for single worst bike I've owned to date. I don't say that lightly.
Again, I wanted to like it so bad, paid a shit ton more than I was used to coming from working for a manufacturer, and as such pretended "it's pretty good!" On day one of team camp where I planned to unleash its lightweight but aeroness. Then the rest of team camp happened and I had to admit I hated it and sold it as soon as I got home.
My experience with the Felt AR has been completely different. I have owned and ridden quite a few bikes and the current AR is the nicest aero road bike that I have ridden and owned. I have had zero issues with BB being flexy after thousands of miles. I don't put as much wattage out in a sprint as some guys on here (only around 1300w), but I have had zero flex from sprinting or climbing on that frame. That BB is massive and very stiff. This bike is awesome and Felt really did a great job with it.
I rode a older S5 before they updated the geometry. That old geometry didn't suit me, but now that they updated it that might improve things. But that older geometry just sucked and I just couldn't get use to its handling and my position on it. I have heard the new geometry really fixed things.
The Venge ViAS might be one of the worse handling, braking and ride feel aero frames that I have been on. That thing was terrible. There aren't many frames that I have felt this way about, but it felt like a piece of lumber when riding around. Even with nice wheels, tires, proper tubular pressure, nice bib shorts...etc. Just terrible for as expensive of a frame that it was. The braking was also terrible and was not confidence inspiring. I felt bad for my buddy that bought it and even he regretted it and eventually sold it off and bought a Trek Madone.
Trek Madone. This is probably the nicest fully integrated super aero road bike that I have ridden. Truly amazing what Trek has done with it from a performance standpoint. Blows the Venge ViAS away. If I was looking to spend this amount of money on an aero frame and wanted one with this much integration and proprietary parts, the Madone would be it hands down.
Canyon Aeroad, I haven't had a chance to ride one of these but this is another one that I would seriously consider if I could easily get my hands on one to test ride and perhaps purchase.