It's all relative. I don't know what your streetbike weighs, but let's go with a ballpark figure of 400 lbs. If you saved 17 lbs. off your bike, that's just a bit more than a 4% weight savings. Now take a moment to consider how much weight needs to come off just to make a similar weight savings on the VX. The VX is listed at 3,955 lbs., so...
1% = 39.55 lbs
2% = 79.10 lbs
3% = 118.65 lbs
4% = 158.20 lbs
5% = 197.75 lbs
6% = 237.30 lbs
7% = 276.85 lbs
8% = 316.40 lbs
9% = 355.95 lbs
and of course
10% = 395.50 lbs
etc.
I'm thinking that if you wanted to just remove 4% from the VX, removing the hood (before you even replace it with anything) AND the back seat probably still won't get you there. And even then I doubt you could really tell a difference - it's still just a meager 4% and the VX is no motorcycle. Shifting your weight while riding a VX won't do much, and your weight relative to the VX is much less than it is relative to the bike. The average guy on a 400 lb. streetbike may represent almost 50% of the bike's own weight added to it, then you're on two wheels too, so it makes a big difference. The VX hardly knows that person is there.
Gasoline weighs about 6 lbs. per gallon and our tank is 22.5 gallons, so having a full tank for us means carrying about an extra 135 lbs. Can you tell much difference between a full tank and when you're on fumes? I can't. It's only between a 3% and 4% weight increase. In fact, mine feels a bit peppier with a full tank for whatever reason.