I have a lot of exposure on both. If you like the thump and low end torque of the 1200c go for it. If you want smooth broad performance go for the Triumph. The Triumph will feel like your V-strom as it has good torque through all bands. But, on performance it will feel kinda like it took a Valium. Remember you are getting off of a pretty zippy bike. Your V-strom in a straight line is about 2 seconds faster than an America in the 1/4 mile.
Straight line 1/4 mile the Sportster if faster than the America by more than a second. Then again if you are a drag racer you are looking at the wrong bikes
They are both pretty darn slow as fast bikes go.
IMHO, everybody has a Sportster, that ain't cool. Triumphs are cool! Oh, they are cheap to maintain, go real good, corner like a sport bike and ummmm, they are cool.
You are on the wrong forum to get a middle of the road opinion. Go get the Triumph and live a complete life. You know you want one.
