I like both a lot and i like then equally.
Both aren't scoring a lot. Pandev scores 10-15 goals in serie A every year, Vucinic is the same, maybe even with a little worse record than Pandev.
Both are playing their best matches exactly against the strongest teams (both score the goals for their NT's against the strongest teams, like Holland, Spain, Italy etc), both were great in Europe with their clubs (Pandev scored 3 goals against Real Madrid in CL 2 years ago and scored against the other teams in the group, Vucinic scored against Manchester United, Chelsea, Real Madrid).
In serie A they usually play great against the big teams. Pandev is simply unstoppable for Juve defenders while Vucinic is always killing Milan.
They're same age and they're both great dribblers and physically very strong (too hard to take the ball from them, they cover it perfectly, especially Pandev).
Vucinic is much faster and is much better in the air, Pandev is a better playmaker and has a better vision. Vucinic is getting injured pretty often, while Pandev's stamina is questionable because he's always "dying" after 70 minutes of play.
Vucinic has bigger experience in Europe, because Roma are CL regulars while Lazio made it only once to CL in the last years, and that's the main advantage he has. When you take everything else into concideration, they're at the same level imo.