He isn't much better, the only difference between the two is that Reid pretends to be a progressive whereas Lincoln is unabashedly to right of the Democratic Party. In that regard, Lincoln is superior.
Lincoln has taken the lead on ag subsidies for big producers and abolishing the estate tax. I don't think Reid would have been there with her, although it's hard to say because he's been party leader for so long and as such he couldn't break from the party line.
She isn't so much to the right as she is a blatant corporate tool. She's against the Democrats on items that are bad policy, not just those that are "conservative." I don't expect any senator from Arkansas to be pro-gay, for example, but what possible reason could she have for trying to abolish the estate tax, nearly invisible in her state, except to help a very, very small number of constituents?
Finally, to be clear, if I thought she stood any chance of winning reelection I'd likely be biting my tongue on all of this criticism, because she's not measurably worse than several of her colleagues and Arkansas is such a tough state for Dems.