Messenger's level of performance is directly proportional to the amount of memory installed on the machine. Don't even think about installing less than 128MB of RAM in the Messenger workstation if you plan on scanning documents more than a couple of pages long.
If distributing paper documents is part of your process, Messenger can save shipping expenses and the valuable time it takes for paper to travel from one place to another. It's not cheap, though; all told you will need about $4,000 to set it up.
Nevertheless, if closing the loop on the paper to digital process is important to your business, I recommend you look at Adobe's latest offering.