looking the docu made by people like Janne, Douglas and this made me think that most aftermarket passive probes out there are just audiophoolery stuffs.
Lo-Z probes have some advantages, but are much less versatile. Try subjecting one to mains voltages or using it in an audio circuit (usually fairly high impedances). A passive probe is much more complex to make, since you can't just use a simple transmission line. There is also the issue of mechanical integrity. How long is that resistor at the end of a coax cable going to last if it is used every day?
A lo-Z probe is not a replacement for a passive general purpose probe. It. A way to lower capacitance without the disadvantage of fet probes ( limmited voltage ratings and psu need)
It is used in high speed probing. Not for gerenal use. I played a bit with them too. They really perform very good. I used it to probe a 500 ps pulser, a 250MHz squarwave and it gave very good results. And as a compare: I have a 500 MHz HP FET probe, 1GHz philips and a Tektronix active probes, three commercial 1GHz hi-Z probes ( strange thing is they are called hi-Z but are made the same way, only with higher resistance so higher Z (100x probe) so where is the border you go from high to low-Z, is it not better to talk about high Resistive but low reactance probes ?
In real high speed use they solder a probe adapter straight to the pcb and that holds the low-Xc probe
That is an other advantage of the DIY probe. Just solder the resistor to the pcb.
By the way, I found that a small capacitor from coax centre to shield improved the performnce. Also the type of resistor. Very funny, tried a bunch off odd choises like a carbon composite that worked very well ( no guaranty they all do) and a wirewound with two trimmers was one of the best, but you had to tune it for other frequencys ;-)