If you're looking for a powerful smartphone, you'll probably be fine waiting for the Samsung Galaxy Note 5 to arrive.
SamMobile believes that it will come with one of two chips with smart money being on the Exynos 7422. The Exynos 7422 will supposedly combine "the CPU, GPU, RAM, storage, and modem on a single chip." This would be a first for the Galaxy Note series.
We still haven't seen benchmarks emerge for the Galaxy Note 5 but it's important to know that the Note series is always among the most powerful on the market. For instance, last year's Galaxy Note 4 had more firepower than the Galaxy S5.
So if you feel like the Galaxy S6 is underpowered for your needs, you might want to think about waiting for the Galaxy Note 5.