That's funny. My first main was I/L and my second and current is a Corsair. Honestly, I liked the IL pre-Big Bang, I don't exactly know how fun it is now, But it's not a complicated class and seems okay. But I have to say that their main 1v1 is the most fun skill ever to use imo.
Corsairs are really nice. We have 4 attacking skills which can be used both ways - 1v1 and mobs, except Rapid Fire. We have a lot of buffs that makes us much stronger. But our HP sucks, unless you invest some time in it. Such as Gollux Set for % hp, link skill, willpower, and more. But again if its about fun: I/L are flashy and nice post revamp. I'd go for Corsair though.