I've only played a gsr once briefly but own a sr300. I believe the neck on the sr is slimmer in profile but may be wrong. The body of the sr is like a sucked sweet, no edges and very comfy. Not sure about pick ups and pre amp. Is the gsr passive or active.
I have bought and sold a more expensive sr600 as I was so impressed with my cheaper 300.
If a bass is better or not is so subjective. see if you can try one.