Round core, hex core. What's your opinion?

[Horgh]

It may have to do with the core-to-wrap ratio. As a general rule, a hex core would feel stiffer than a round core, provided they're of the same diameter. But it's very possible a hex core of a small diameter can feel more flexible than a round core of a larger diameter.

For example, GHS Round Core Boomers 45-105 would feel stiffer than Dunlop Super Bright Nickels 45-105 (hex core) due to the difference in the core diameter.

Interesting. I figured since they're both DR they'd use the same machines/winding/designs, but maybe not. I suppose with any "signature" product you can have variations from the norm. Both feel good, I really like DR's coating, but yeah, the Bootzillas feel really nice.

 

[LetItGrowTone]

On strings with thick hex cores the overtones sound sharp to my ears.

Yes, the science is solid on that, covered in several threads.
The key is more vs. less flexible (which does not always equal round core vs hex, but usually does.)
One more type now, Dogal Hellborg with a stranded core, even more flexible.