Default SMS apps that are lighter in memory/cpu usages and as bug free as Hangouts

Hi,

I just wanted to ask that I am not sure how much memory/cpu usage/battery drain Hangouts causes, but are there any alternative SMS apps that are as bug free as Hangouts, and also lighter in memory and battery/cpu usage? Also, I find Hangouts a little ugly and bizarre, but so do many other reviews by users and sites.

Thank you for any recommendations.