I own a VT-1 535, and I have been very happy with it. You will see a solid gain in the 0 - 60 range. You really feel the difference at the RPMs are in the 5,000 on up range.
As a daily driver, it will feel like stock, but when you allow the RPMs to climb, it becomes something dramatically faster and more powerful than stock.
One situation where I see as very different from stock is in the passing power capability. The speed climbs very quickly as the RPMs build. In fact, 60 - 100 happens in a little more that a blink.
Like I said earlier, you will get some improvement in your 0 - 60 time, but much of really contributes to low times in that time speed range is your ability to retain traction. Even with the VT-1 535, you can break the tires loose in 1st, 2nd, and 3rd. Getting the traction needed to really impact the 0 - 60 time is still an issue.
For your purposes, I am confident you will have NO regrets going with either the VT-1 535, or the VT-2 575. In fact, you likely won't see any difference between the two in the 0 - 60 range.