Safari uses the gpu to help render pages, so it's going to drain the battery faster with every page load. I've also noticed my system runs 10C-20C hotter when using Safari.
My recommendation: Chrome.
Doesn't need the GPU. Less CPU usage. As such, it runs 10C-15C cooler with the same tabs open...while remaining just as fast. It also has better extensions and a decidedly better unibar. Lastly, it's also more stable with a high number of tabs open. With Safari, I've even noticed that long pages now actually go blank like on the iPad for a moment while the gpu or whatever catches up. It's kinda sad, really.
How you go forward is your choice, but if you want better battery life than you're seeing out of Safari, Chrome is your next destination.