[Dragline45]

He goes on to point out that the straight-thumbs technique requires special considerations when shooting a 1911, a SIG, a Glock, or a revolver.

None of that is true except for the revolver. There is no reason your grip should change when shooting a Glock, Sig, or 1911. A revolver is a different story as it is unsafe to have your thumbs that close to the cylinder gap.

Given all of this, I am wondering if it is worth my time to retrain myself for a straight-thumbs grip...

Personally, I would say yes. With enough practice using the thumbs forward grip and enough familiarization with a particular pistol you can put shots center mass without ever looking at the sights. Also with a thumbs forward grip when using sights, I can quickly and more efficiently get my sights on target and aligned from the draw. Thumbs forward grip is also great for managing recoil and followup shots. This is just my experience, but the particular grip allows the gun to naturally point for me. When I started using this grip a few years ago my groups immediately tightened up, and most importantly my first shot from draw was always dead on.

I feel like my current shooting skills are "in the groove", and I don't want to screw them up by changing my grip... UNLESS I can achieve a whole new level of performance. But if it is going to take dedicating myself to shooting every weekend for the next year... well I can't make that commitment.

No matter how good anyone's shooting skills are, there is always room for improvement and more to learn. It took me one or two range trips and dry fire practice to get accustomed to the thumbs forward grip, so I would not worry about having to learn this over a long period of time. Don't take dry fire practice for granted, you don't need to be at the range actually shooting to hone your skills. Practice drawing your pistol until you can naturally point and have your sights on target every time. Dry fire till the sun goes down to get a good feeling for the trigger and practice your skills.