Your 2nd question first: Yes, re-election is a reward. In all but a few exceptions, a grossly undeserved reward. They get much better perquisites and pensions than us serfs. You want medical care reform? You should see the benefits that "royalty" gets compared to what most of us get or will ever get. Each term gives them more opportunity for direct and indirect payoffs. They all retire much more wealthy than when they start. And for what? Driving us into slavery (rules, regulations, surveillance, searches and seizures, taxes, fees...) and poverty (credit expansions and contractions, shipping jobs overseas, allowing unlimited illegal alien swarms...)
Now as to a report card, that is an interesting question. You probably won't get many answers. But here is the basic criterion. Grade them "pass or fail" on their votes on bills as to whether they uphold or trash the US Constitution Bill of Rights and various sections in the basic Constitution.