The interface is a little clunky compared to Facebook's Ad Manager. However, it is still easier than the average software interface, which has driven more than a few people to alcoholism.
And unlike Facebook, you cannot experiment by just putting a couple of dollars behind a boost. So far the smallest daily budget it has allowed me is $15. The workaround is to fire off the campaign, monitor it, and then pause or stop it after its has spent just a few bucks.
Targeting people by job title is better than on Facebook. On LinkedIn people tend to put real job titles. On Facebook even corporate executives tend to put job titles like "Lord of the Dance".