I am also on a Mortgage-One loan, and so far I am very pleased with the flexibility. I have not much info on the current flexi loans by other banks, and only some maybe outdated info of that offered by Citibank years ago. But I think a flexi loan is not suitable for everybody. It is suitable for people that
1. Wants to take a longer loan tenure (to reduce minimum monthly repayment) but has the intention to repay in full before the full tenure
2. Has the financial capability to pay an average monthly amount higher than the minimum amount
3. Has the discipline to act according to pt 2
4. Net positive cash flow every month, and income is much higher than the minimum monthly repayment

I see pts (1) intention, (2) financial capability and (3) discipline as necessary in order to benefit from the flexi loan, and (4) is optional. And I think the prior discussions in the other forum did not take pt (4) into consideration. Let's look at an example:

Salary: 100%
Minimum monthly repayment: 30% (this includes paying towards principle and interest)
Personal savings: 20%
Monthly expenses: 50%

I assume that all salary of 100% is deposited into Mortgage One, and the savings of 20% is also kept inside always reduce the interest. These excess payment of 20% per month also serves as emergency fund, and can be withdrawn at anytime. Remaining monthly expenses of 50% is typically not used up in a single day. For simplicity sake, I assume it is evenly distributed (ie. you "withdraw" from the bank an equal amount every day) and hence on average, 25% of your salary (50% / 2) is in the account to help to reduce your interest (but they do not reduce your principle, since at end of the month, they are fully withdrawn out). Therefore, a total of 30% + 20% + 25% = 75% of your salary is contributing to reducing your monthly interest and principle.

In a less flexi loan where penalty is incurred when withdrawn, then 30% + 20% = 50% is contributing. And in a conventional loan, only 30%.

Therefore, the Mortage One loan is working out very well for me. On average, I am keeping more than 2X the monthly minimum in the A/C (eg. if I need to pay 1000/mth, then I maintain at lease 2000/mth), I withdraw my expenses only when I need them (eg. pay bills only when they are abt to be due, but make sure I pay in full the CC), and so far, after abt 5 years of repayment, my monthly interest has reduced to <50% of what I started out with. And all these, with less headaches in how much to plan for emergency fund, and how much to prepay in advance etc. I also got hit with something similar to b00n, where a family tragedy needed me to withdraw close to total 20K within 2 month, but spread over a few times, but accessing the money was a snap, and no extra charges incurred.

Finally, I do not think the Mortgage One plan is so suitable for businessmen, as it is unlike an overdraft where you can withdraw up to your original principle. In Mortgage One, every month, the portion that is paying towards your principle is "frozen" and is not accessible anymore. This is how the bank reduces its risk. Therefore, towards the end of the loan tenure, you can only withdraw a small portion of the loan. For businesses that require more flexibility, other loans might be more suitable.