Bigger units are not so easy to divest, esp those > RM 2m. I would advise not to over leverage on projects > RM 2m due to MYR high interest rate. Unless the MRT comes to Lido Boulevard area, I personally think making a decent profit on this investment may well prove challenging.
Looks like most of the upcoming units in Singapore are the shoebox units. Large, spacious units are still in short supply and unaffordable in Singapore. Landed units are still breaking records, one after the other.
To be able to live in a large, spacious unit will be an added attraction to move up North. So, my feeling is that demand for landed and large condos in the right location will not be that bad in Iskandar, in the long run, when more Singaporeans look towards the area.
That said, I definitely agree that one needs to be mindful of the interest rates. For a 25 year loan, they monthly payment will be 40% higher @ 4.2% (Malaysia) vs. 1% (Singapore). They key difference is in Singapore, most of the payment goes towards equity, in other words reducing the loan, while in Malaysia, a big chunk of the payment goes towards interest.