I would if it was me
I started with a 2013 ST-S. Also have a 2008 GS. Rode friends 2011 RT to decide if I wanted an RT. You are right, my right foot baked!! We saw and bought the 2016 RT-S (1330cc). The frame style and tupperware have been perfected (well it works!) and there is NO heat on my foot.
The other thing is the 1330 engine - has a huge power curve. I pull a trailer once in a while, and cannot even tell it is there. You actually have to roll on the throttle a ways to get moving. 15" front tires versus the 14" on the older models.
On the flip side, the 998cc 2008 GS is a rip-roaring burnout let me at them curves ryde!! You are more in a crotch rocket position though. Not great for my old bones for long trips. The RT is made for more comfort. Wife and I rode 2-up 8-10 hours a day and barely had sore butts. Super comfy with the BRP comfort seat that you get with the 2016!
If you are looking for something you plan on going on long trips on, I personally LOVE the 2016 RT's. Your older model probably is very close in comfort levels, but it does put out a ton of heat. I have seen a few complex heat re-direction kits out there. They come with insulation that goes on the radiator, inside tupper ware. Plus pieces that direct the air flow down below the pegs.
Oh - pegs! The 2016 has the large, rubber padded boards for both driver and passenger. They really eliminate road vibration. Combined with the deluxe seat the comfort level goes way up. But is it worth it? I wouldn't go back. The 2016 is so comfy that my wife wanted to learn how to drive and got her license. She did not like the pegs at all - but she had never driven a bike in her life either.
If you find the big heat kit, might be worth a try before spending the money on the 2014+ 1330cc models. If I see it I'll post a link here.
Just my two cents
Steve