Re: TFO medium fast vs Winston fast
If you have things figured out to make that 7 weight work to your satisfaction, I'm pretty sure you will have no problem with the GVX after a few minor technique adjustments. There should be a diiference between any 5 and 7 weight so it will just take a little getting used to.
Neither of the rods you mentioned is off the charts as for being too wimbly or too stiff. You'll catch on quick I bet. If not, tweaking the line you use can customize the rod more to your taste if need be,