Like I said, it depends on your need. Strangely enough, I work in the legal field also. I'm the lead software developer at a company that builds computer legal research systems. I've overseen the scanning of millions of pages. Our most recent big scan jobs included scanning the entire F.2d and F.3d series from West, all of Wests F.Supps, and all case law and statutes from an African nation.
I'm guessing you don't have anything of that magnitude.
At a level like it sounds you're probably scanning at, that HP would probably work just fine. The only thing I could think of that you'd be better of with a different model for would be the scan quality. That appears to be a color scanner, which uses a standard white bulb. The scanners I pointed you to are B&W or grayscale only. They use a green bulb, which enhances the contrast if you're scanning text only documents, which can give you a better source to OCR. That would be the biggest advantage I can think for your price range.