I asked a similar question awhile back. Perhaps the answers located here may also be of assistance as you evaluate what would be the best fit for your organization. Based on the feedback I received from stackexchange, I modified our process to a mini-regression suite at every release. It tests only the showstopper level features. If I don't find bugs, I can finish it in around 4 hours testing simultaneously on 2 different platforms (OS level and internet), including our mobile app and device communications such as time clocks. I am the only tester; there is no automation for our mini-regression suite. If I find bugs, naturally it takes longer to finish the mini-regression.

Here is the link. Let me know if you have any questions. Internal Acceptance Test (not automated): How long should it take?

I asked a similar question awhile back. Perhaps the answers located here may also be of assistance as you evaluate what would be the best fit for your organization. Based on the feedback I received from stackexchange, I modified our process to a mini-regression suite at every release. It tests only the showstopper level features. If I don't find bugs, I can finish it in around 4 hours testing simultaneously on 2 different platforms (OS level and internet), including our mobile app and device communications such as time clocks. I am the only tester; there is no automation for our mini-regression suite. If I find bugs, naturally it takes longer to finish the mini-regression.

Here is the link. Let me know if you have any questions. Internal Acceptance Test (not automated): How long should it take?