I will share my and my extended families' actual experiences with Death Taxes, Donation vs Sale & the taxes thereof.
Death taxes (para madali natin differentiate from other transfer taxes) amount to actually nearer 40percent. The basis lies in the way the BIR valuates the properties. Kung icuento ko pa lahat ng twists and turns involved with taxes after death -- when every govt agency has its version of -- Hindi tayo matatapos dito.
For me, Donation is the better route to transfer properties. Not due to costs but Eto ha, tandaan nyo, hindi ko uulitin ito. Haha -- the BIR can not shake down the persons who receive a donation. Kahit na ga-Malacanang namana.
But kung transfer made through a Deed of Sale, 1 fine day -- kayang kaya ipitin ng BIR yung napa manahan. Discrepancy between declared income and value of assets owned. Patay kang bata ka. I have a cousin who found himself in a laughable situation. Tax deficiency of 12million for just 1 year, eh in any 1 of past 3 years never sya lumampas ng 2mio earnings per year. Ineffable! Lol
It is best to transfer properties while alive ang givers. But that takes guts. Really.
The givers must overcome their fear, if any, of being treated shabbily PAg makuha na sa kanila assets. Takot sila to be on the begging end for their needs later on. Well, power resides nga naman in who controls assets.
Then, mahirap I pantay pantay if the givers have more than 1 heir and more than 1 property.
But the advantage in giving before dying is -- sigurado ka yung gusto mong puntahan ng asset mo eh dun pupunta. Whether fair/unfair -- is irrelevant (they can give even to non-heirs. Kaya may mga ma tsing na kab1tches. Hehe).
Atchaka, if you DONATE while alive kahit sobrang unequal legally ang distribution ng heirs -- what can they do? Ignore you, at most. Lol
Pero kung Deed of Sale gawa mo, at may anak/heir na dejado or swapang -- pag dead-do na giver, puede pa I-challenge in court the Deed of Sale -- again, based on the "buyer"-heir's capacity to buy nga naman. Nothing like money to tear families apart.
So, TS ANN08 -- do it through a Deed of Donation.
While both parents are/1 is still alive -- ano ba namang hayan mo na sila makinabang sa pag collect at control ng rentals? For sure, you will let them continue to control the rentals (pero bayaran nila real estate taxes, maintenance costs etc...

. Puede pag-usapan)9
Pay-up now. You cannot escape taxes, like Death. Postpone it, well the tax bill just gets bigger. San ka naka rinig ng taxes na bumaba?
The govt entities find ways to always jack up assessments, and taxes.
Patagalin mo yan, you will pay a bigger Donation Tax or Deed of Sale Tax later on. For sure.
As it is now na nga, marami na kusot with BIR sa taxes for property sales. Dati, based on whichever is higher: actual vs zonal. Anak ng hito -- they have their 3rd or own assessed value. Ineffable!