thank you all for the compliments. the bike is certainly a looker, and i am happy with the result! i forgot to mention that the 6.57kg weight is with the garmin, so i might be able to say that i've already hit the 6.5kg goal.
but, i will still be slimming and trimming here and there.
responses to a few inquiries:
1.) Wheelset: rear wheel weight = 712 ; front wheel weight = 564. total 1276. that is WITH rim tape WITHOUT skewers. light as hell and solid enough for me (i weigh 72 kg during my 'on form' moments; weight fluctuates up to 76 during the sad wintry months). i use them everyday, all-day. the only time i don't use them is if i know i will be hitting a bit of gravel or dirt during a ride. that being said, i have come across some gnarly stuff by surprise with these wheels and they are solid. i cover all kinds of roads: good, really bad, and everything in-between. they have stood up to 3,000 miles (5,000km) with no issue. had the rear wheel trued once after about 1,500 miles, and i need to get it trued again as it is slightly off... but, for the weight they are solid- i can't detect any flex - and they are definitely durable. Fairwheel Bikes built them up, and said they are sometimes hesitant to recommend the Ryde Pulse Sprint rims (average 395g per rim), but i insisted and am VERY happy. kudos to Fairwheel. they are wonderful.
2.) EEBrakes: Holy wow. some things you can just TELL are premium by the way they feel in your hand and the way they mount on the bike. i was a little hesitant when i read the directions and saw all the little pieces and bits (and the direct mount front comes with a tooth pick to help with installation haha), but it is not as complicated as it seems. the direct mount is definitely a step up in power from my SRAM Red Aerolink caliper, and the normal mount rear is just as good. granted, i have only done a short 20-mile test run in the dry, but after a couple miles i forgot to think about the brakes: they work very well. and look so nice. and feel so good haha.
3.) Frame weight: So, after building this thing up, i now have a bit better idea where some of that mass comes from. the frame bits (cable stops, bottom bracket cable guide, front derailleur mount, etc) are all SUPER solid. i think each one adds an extra 6-8g over the equivalent of a Scott Addict TEAM ISSUE or Cannondale SSEHM, for example. the Xelius SL bits all attach with little bolts and are all extra large so when remove the frame has big holes, easier for routing the internal cables. this was by far the EASIEST internal cable route build i have ever done (barring the frames from manufacturers like FOCUS who have inner lines that guide the cables). 2 minutes to get the derailleur cables through the frame and to the derailleurs. i am guessing there is about 35 grams of extra weight just in the extra beefy frame bits and pieces.
4.) the ride: as exFictitiouZ said, the ride is pretty sweet. i am coming over from a 2016 supersix evo hi mod, so the bar is high. compared to that, the front end of the Xelius SL is def not as compliant-- the crappy roads i ride were talking to me much more loudly through the bars, but the rear is even smoother than the super six, and that is saying something. the supersix is all-around more balanced in front to rear compliance, while the Xelius is much smoother on the rear than its front, which maybe makes the front seem harsher than it is. that being said, the Xelius absolutes glides through sweeping downhill curves. unreal. i did a mental double take when i was coming down a 7-8% grade into a long swooping corner.... it felt like the bike wasn't even touching the ground, like i was cannonballing a greased toboggan across the smoothest sheet of ice you can imagine. not a good comparison, but i literally laughed out loud as i hit this curve. i am excited to get some more time in the saddle! as for stiffness-- it feels solid! just as solid as the supersix, but the comparison might not be fair as i had an aluminum chassis quark dzero on the ss and a carbon chassis dzero on the xelius... either way, it will WORK for me.
more to come as i continue to trim and slim and ride.