Let's see... you are on a Titleist site asking Titleist enthusiasts if you should use Titleist or another brand? Hummm. I would say, make the switch.

I would strongly recommend a fitting, even if you don’t end up buying new clubs, the experience and getting feedback from a track man is fun and beneficial. If you go to a respected and trustworthy fitter - they will be honest about your current sticks, and if you need an upgrade.

I would definitely go try them out and compare them to you current set. I absolutely love the new look and feel of the new T Series irons.

I just switched from 2004 845 silver scots to the 2019 T200s and have no regrets. A slight change in look at address and a little less forgiveness but much better feel and sound with a pure strike. Oddly enough I don’t mind the loss in forgiveness as the T200s allow me to feel where I missed. It’s easy to tell if it was thin or off the toe. Allows me to see what I need to work on versus clubs that are too forgiving that mask flaws. I would definitely get fit or at least go somewhere to hit balls and see how they feel.

That’s a thousand dollar question (5 clubs). It might cost you $100 to take the Bertha’s to a fitting and then stay with them. But you will have clarity.
Just don’t spend a grand on clubs you weren’t fit for.