The big bonus to a CVT as far as I am concerned, is the fact that you reap the benefits of a multi-speed power transmission in a fairly tidy, automatic package. What this allows you to do is get away with gear ratios that would be too high with a c-clutch. Taking Russ' example (and not knowing tire size), he's running at 4.2:1. Now, let's suppose that Russ cannot gear any higher because he'd lose valuable launch torque, and/or risk overheating his clutch. So, his maximum road speed is, well- his maximum.
Now- let's consider that a CVT like the Comet TAV2 has a low ratio of 2.7:1. If we apply this to Russ' existing ratio, we end up with a compound low ratio of 11.44:1. Mega launch.
Now what? Well, 11.44:1 is gobs more low than you probably need for your application. We all know that acceleration and top speed are a trade-off. To gain one, you lose the other. So let's trade off. Let's for theory suggest a top speed increase of 15%. With a c-clutch, you'd have to regear to 3.65:1 for that 15%. Too high? No problem for a CVT. Apply the CVT's low of 2.7:1, and you have a compound low of 9.86:1. Still low enough for a good launch, yet you've increased your top speed by 15%.
Wait- it gets better!
The TAV2 (and knockoffs) boast a 10% overdrive- instead of having a high ratio of 1:1, it's actually 0.9:1. So, your top speed has increased even further yet.
Naturally, there are more factors involved in getting all this right than this, but this is an illustration of some of the benefits.