Would you use interactive brokers or saxocapital to trade US stocks? And why?

Interactive Broker is very cheap, with the lowest fee in the world (probably) and the widest range of products.
They are known as mass-market stock brokers.

If you are doing only $100 a month, it can still be cheaper in IB despite the $10 monthly fee by IB, if your stock is bought in overseas currency. This is because IB's forex rate is hugely with no hidden spreads in some banks and brokers. You're saving quite a big difference in the forex.
1. The commission is the lowest. (some products are negative commission, means you get paid to trade). Most of my commission is $1 or $2 for 100 stocks. And I get paid commission for trading in non-popular stocks as I adding liquidity to them.
2. Variety is the widest in this broker.
3. Forex rate is one of the most competitive (a lot of brokers have hidden fees due to the spread)
4. They have a local Citibank account, so you can FAST transfer SGD, and the SGD reflected in your account within minutes. Then go platform and exchange to USD or whatever you want on your own.
5. $10 minimum fee, so if you only trade $4 this month, they will charge extra $6 to round it up to $10.

5 is a bad point, but 1-4 makes it worthwhile.

Interactive Brokers minimum commission is $1 USD but there will be a $10USD monthly fee if the total asset under your account is less than $100K USD.

On the other hand, Saxo Capital minimum commission is $3.99 USD and the monthly fee is 0.12% of total asset under your account.

I would therefore prefer to trade using Saxo Capital until I have $100k USD then I will switch to Interactive Brokers.