GT tyres are designed for heavy torquey bikes like Pan Euros, GTR1400, FJR ect.
Putting them on a strom it a bit overkill and can negatively affect the handling if not used on a bike heavy enough to justify the stiffer sidewalls.
The tyre supplier I used to deal with for work said on a bike less that 260kg it's like putting 50psi in the front tyre.
You'll get no deformation of the round prifile of the tyre where the tyre contacts the road.
Decreases the contact patch and makes the bike twitchy.
I asked for SWMBO's GSX1400, he said:
"Well yes that's a bike with a lot of torque, and the GT will last longer, but unless you only ever ride it 2up I wouldn't advise it."
Old Git : your RT will be fine with them but I wouldn't advise them for the Strom.
If a tyre dealer is offering them in Strom fitment, he's not advising, he trying to get rid of something he ordered for someone and they backed out of buying them.