The ability of catapult can send mass text messages at one time which makes it better service for me as I have limited access through internet due to poor network connection but still able to receive those texts by using WhatsApp App via my Android phone.
It has no negative point that i know so far about this product from users's perspective who are active user or not! If you want faster way you should use whats app since they already provide such kind feature while sending out sms message will take much longer compared when we do same thing within our smartphone application itself.