Tested on a V-Strom 2008, first time using full synthetic at around 100,000 km. First, I put in 10w40 for the winter. The gearbox was smoother than ever, even in first gear which usually engages harshly, and even after many hours of continuous riding. However, I was a bit concerned with this one because I could hear the engine as if it was running rough or its operation sounded quite loud, so I changed it after 5,500 km.
In the spring, I put in 15w50. The clutch/gearbox was just as good but not as smooth (before warming up) as with the 10w40. However, the engine ran silky smooth under any conditions, even after 4-5 hours of continuous riding. Meanwhile, for the first time with oil, I felt differences in the bike as if there was amazing compression and explosiveness in the engine—I don't know how to describe it, as if the engine had become stronger and was ready to launch as soon as I gave it throttle. I've done 7,500 km with this oil (15w50) and I still don't want to change it, it works perfectly—I think I'll change it at 8,000 km, although I think it could last up to 10,000.
The downside of both oils is that after 3,000 km it started burning oil and I had to top up about 200-250 ml every 2,000 km, but okay, that's a normal amount.
Conclusion: if you switch from semi-synthetic to this, you won't look for semi-synthetics again, and most importantly, it's cheaper than most cheap semi-synthetic brands and all the well-known ones. I would only recommend the 15w50 and whoever tries it will remember me.