I’ve recently started fooling with HHTs and HBCs and have been pretty impressed (so far).
I don’t think I’ve wasted a moment worrying about the process of having to tip them. It’s something the kids enjoy doing with me just like every other step of the reloading process.
I’ve clocked BCs with a LabRadar (calibrated against bullets with lots of data in Litz’s database) for the .358 and .366 caliber offerings. In those calibers, BC seemed to run fairly consistent with estimates in the website. Only one of the four I tried ran significantly less than advertised (and it was clearly marked as an estimate on their website). However, one other (the .366 242gr HHT) significantly exceeded what they had listed, and that's becoming one of my go-to 9.3mm hunting bullets:

*All of the above are averaged across at least 10 data points with Kestrel sourced atmospheric conditions.
I’ve heard that their tipped BCs run a lot truer than their open tip BCs. Seems to be a well documented problem they had at one point, but maybe they’re learning from it.
I’ll be trying .308, .264, and .257 offerings as the summer progresses. It could also be that the accurate or conservative BCs I’ve found so far are just a function of the larger bore diameters. It could also be that they haven't tested a lot of their larger caliber BCs, and are choosing to be somewhat conservative in their estimates.
I've also noticed the higher velocity thing. The 242gr HHT is moving over 2700fps from my 23" 9.3x62, and I'm still not into pressure signs. I can't get there with a 250gr AB. Every one I've tried has shot MOA or better, noticeably more accurate than the AB or TTSX from the same rifle.