I wouldn't jump right to that. Even with the nerfs, I suspect jayce's large ability pool will still be useful.
What I would focus instead on would be positioning, and proper cooldown cycling. Most of the problems people lose to are not character based, but decision based. Don't get me wrong, a good gap closer champ (like fiora) can rofl stomp jayce, but they still need to A) know how to play against him and B) position properly. Perhaps get someone that is really used to either playing jayce or against jayce to duel with, so you can get advise from them. I'm not really a jayce player, but I know his abilities, and might be able to offer you some advise if you want.
Add me, if you want a duel.
Also, one of my Diamond friends is a Jayce main, and he does free coaching :
http://boards.na.leagueoflegends.com/en/c/tips-tricks/W7KqoJiI-free-coaching-from-diamonds
Maybe swing by and watch/ask him.
-T