Difference between Digitech GNX 3 to GNX 4

[LesPaulCustom]

<font color="yellow">I don't know how many JCFers use these units.

I realize that there is a significant $$ difference between the 2 units, but, what does the GNX 4 offer over the GNX 3 that makes it worth the extra expense??

All I really want to use it for is practice and transcribing etc.

What are your thoughts on the 2 units and comparison??

Thanks.
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