If you are looking at condos with Enbloc potential, it means that there are already talks about enbloc or it has already failed many times. When there are talks about enbloc, the owners will usually try to sell it at a premium to cash out earlier.
If you are looking at a time frame of less than 10 yrs, i would suggest that you put that some of money into commercial property that can give you a better cash flow and much higher capital appreciation.
If you are going for more than 10 years, get a freehold property that is close to MRT, you will have a lower rental yield but property like those are good for holding long term.
Just my opinion.