I've been working off-and-on with LSD out of OK for a few years.  Historically they are very slow payers. However, it appears that they have restructured a bit and have a new person doing the accounts payable.  (The last invoice I sent was paid in about 2 weeks.)

My only real complaint is that they smother you with telephone calls which start within an hour of them sending their order and continue until you send the completed search back to them.  Otherwise they really are not bad to work with.