Depends what you want better handling skills for.
I've found my skills in various areas have improved as I've needed them to. I commute, so I've picked up assorted tricks for riding in heavy traffic.
To give a better idea: Riding on my own I was safe and had no problems. When I joined a club I had to learn how to ride in a group, this improved my ability to ride close to others, do through and off, react to other riders doing the less expected etc. Chaingangs have honed these skills. Racing has taken them to a new level - my ability to descend in particular has improved massively over the time I've raced because it's no good getting to the top of a climb if you can't hold a wheel going down. Previously, that was not a skill I needed or thought about, I improved it out of necessity. Equally moving up in a bunch of 80 riders riding at 25mph+ is still hard work, but nowhere near as hard as it used to be.
TO paraphrase the saying about improving speed: you'll never be able to corner at 25mph if you don't corner at 25mph.