I'll purchase the conversion kit in Thailand as soon as my toyota warranty ends. Braking would still be superior when comparing a disc vs. a drum. 1) better heat dissipation. 2) easier to maintain since replacing disc brake pads is hella lot easier than shoe pads. 3) once you wade in a flood prone area your drum brakes automatically suffer... water and dirt gets stuck inside hence making braking very hard and wearing the drum itself.
I've done a couple of DIY conversions as long as you have the basic tools then you're good to go. I did it on my old starex and fortuner and that was more than a decade ago and the aftermarket disc brakes are still in great condition. The price is quite affordable around less than $200 so you wouldn't be taxed by customs now unlike before. ;) P10k above ang taxable ngayon ata sa customs.
good for you, sir!
but for everyday driving, driver will probably feel very little, if any, difference.
except for the occasional flood wading, that is.