V. MQTT PROS AND CONS
Each protocol has its own pros and cons so does MQTT.
A. Pros
Light weight API requires minimal processing on a device hence its very much suitable for devices that consumes low power. The message headers can be as small as 2 bytes which makes MQTT bandwidth efficient and ideal for spotty coverage or limited networks. MQTT-SNN (Sensor Networks) supports topic id instead of topic name and UDP, Zigbee, BLE and many other wireless protocols.
B. Cons
MQTT has no section for message properties and no support for such header fields as TTL. Besides it does not support message queuing.