New Cartridge Time

Rega p3

We'd probably need to know what type of sound you are looking for

Is the Charisma 103 another one of those modified DL103s?  If so, I would look elsewhere, if you want a really different experience.  You can only flog that old horse so many times.  I have no idea at all about a Grado Sonata, so can't help there, but if you are fixed on these two, I would go with the Grado just because.  If it's suitable for your tonearm, as Chakster implies.

from a recent fortune cookie from chinese take out ordered --

"questions asked with some consideration and effort will yield the most thoughtful and applicable answers"

😆

There are much better cartridges than Grado available for your tonearm.

But using low compliance DL-103 on Rega is just a demonstration that you don't understand tonearm/cartridge matching theory, read here.  And your dealer too.