I never used localbitcoin so I am not able to tell you anything about it. May be others members in this forum who used localbitcoin can reply here with his experience. For Wazirx I can say I never have any issues regarding buy and selling bitcoin and they have a good liquidity in trading. So you dont have to wait for long time for matching your price order because there are so many people keep buying and selling bitcoin. I recommend to watch you this viedeo for how to buy and sell bitcoin on Wazirx. https://youtu.be/YbAvLGXKH2k