My brakes are fantastic...hold completely at full power with handbrake or toe brakes and have very significant braking power as soon as the majority of weight load is on the wheels... not sure why yours wouldn't as every disc brake i have ever had, i have been able to get to perform well unless the pad becomes contaminated... Id suggest at least some of you may have contaminated pads,fluid or air/bubbles in the system...
In my experience with lots of disc brakes which is reasonably significant, particularly with motor bikes and mountain bikes, id suggest most issues come from , not conditioning the brakes with initial use, poor bleeding, bubbles, contamination of fluid, mixing of incompatible fluids, oil or other contamination of pads (including general contamination from tarmac oils contained, particularly in water on the runway with initial rain showers).
Im not including fade...just initial braking power... Fade from my experience has a lot more to do with the weight, duration and cooling capacity of the disc.... and is generally completely different to initial braking performance.. (having said that most that desing a setup with great cooling for said load , have a ton of initial braking performance)
My discs are a joke and my calipers are pretty low grade materials, with no venitaltion, they are not straight and they are tiny and made from what looks like scrap tin... but when adjusted properly and bled properly I rarely find many disc brakes that are not fantastic for short durations... and i classify any normal landing scenario in a sub 600kg aircraft as short duration... unless the brakes are significantly under engineered...and i suspect there wouldn't be many smaller and lighter than brake calipers or discs than mine...
We have had 3 brake issues that let to poor braking in 350 odd hours and as soon as identified we fixed them and went back to fantastic braking...