You cannot compare, example SEC with BDO because the types of property and rental rates are far different. For the same sq ft, BDO can rent out RM1600/mth, but SEC rental rates is around RM2700-RM3000 /mth. Since SEC is strata titled with facilities property, is similar with a luxury condo.
Since many owners of SEC bought not for own stay, it is totally a waste if you not able to use the facilities regularly. Inability to rent out units will be a real disadvantage to SEC investors. Those working in singapore will not consider to rent SEC because the place is so deep and jammed. They prefer places near EDL highways, 2nd link and CIQ. Leaving the unit vacant will also cost so much problem. Those come back for weekend stay will also eventually comes back on a monthly basis...and than later quarterly basis.... the whole place will be like deserted and is a potential ghost town / taman. Same problem will face by eco spring / summer buyers. Not trying to be bias, but i understand that sometimes truth hurts.
If I were to invest in real property, apart from rental yield to help defray mortgage payments, future capital gain is equally if not more important.
In my view, SEC is more exclusive (than BDO) and therefore one should be expected to pay/value more. This is my personal opinion. I would like to repeat that different people think and decide differently. I have always owned S'pore cars, the most expensive car in the world, and I have Ang Moh friends who are richer than me but refuse to pay the ridiculous high price for an SG car.
I am not currently vested in SEC, but I may one day relocate from my non strata titled G&G to SEC simply to get back to a similar lifestyle I am having in SG now. You see, the ratio of number of units to facilities in my SG condo is low. So, whenever I want to use the gym, sauna, swimming pool, it is always NOT CROWDED. The pool and sauna officially close at 21:00, but I have often used these facilities after closing hours. The maintenance fee is naturally high, but I don't begrudge it. This is what I will miss when I relocate to enjoy landed (not condo) living in JB. If I miss my SG lifestyle enough to see me putting money on an estate with facility in the future, I will be realistic and definitely am prepared to pay a premium.
I am not here to win an argument with you, I am merely stating my NOVICE opinion. There may be like minded people, or perhaps I am the odd one here. Whether you speak with AUTHORITY is not for me to judge.