Hey all. Just wanted to chime in now that I've finally had some real experience with this frame.
The other night I helped a mate finish his Velobuild build. I've read through this entire thread, and whilst some of the issues some of you guys have been having was a turn off. I've always taken reviews with a grain of salt (because nothing beats personal experience). Almost a year ago now I suggested he buy this frame and for the good part of this year he's been buying parts for it (was waiting for the new Magene groupset but in the end couldn't wait anymore so he bought 105 Di2 from Ali Express).
Build came together great. No issues at all except for a weird rattling noise when dropping the bike a few cm off the ground. Turns out it was a small metal collar in the Mavic style quick release thru axles (such a weird design!). Nothing some thick grease won't fix.
Test rode the bike in the carpark when we were done and holy shit. From the first pedal stroke I knew it was not bad at all. Agile, gets the power down and accelerates really well. It's stiff. I'm well impressed and quite surprised. Felt like a Tarmac, big time. I was left with mixed emotions... wasn't sure how I felt about it all.
Yesterday he took his new build out for it's first maiden ride and let another one of our mates ride it (powerful guy who used to own a Giant bicycle shop, has designed and sold his own frames and who's also ridden and praised my S-Works SL8 Tarmac for having "free speed").
Old mate was mightily impressed, yelled out "free speed!" and said it felt a lot like my SL8. Definitely spun him out, so much so that he literally bought the TanTan SL8 copy last night.
I've always had the thought that building up a cheap Chinese frame would be a lot of fun, but I've always failed to see the point. IE: It'll be good, probably, but it'll never be as good as the real thing... so why bother? I've now come to the conclusion that there's more nuance to it than I originally thought, mainly due to how cheap these frames are in comparison to the real thing.
Sure, layup, weight and quality of the carbon might not be the same, and that could explain the bike feeling stiffer and less compliant than my SL8 (though the SL7 was less compliant than the SL8?), but it's definitely a fast bike so it suggests that geo is WAY more important/evident than layup.
Side by side his size 52 Velobuild setup looks bang on the same as my size 52 SL8 in terms of geometry. Maybe I was secretly hoping it was going to be trash and now I'm going through the motions.
Ultimately I'm mighty impressed and looking forward to riding it again, as well as testing out old mate's TanTan SL8 when it's ready to roll.
TLDR: This frame is good.