Great thread!
I would like to point out that really, there are only two major vin decoding companies out there. They both do a sufficient job. The actual problems are in two areas.
1) The software we use to obtain the information from the vin decoding company. Many times this info is passed through several software apps prior to being published i.e. DMS, IMS(HomeNet), then off for pricing analysis, then to the website or an online classified. The vin decoder may decode and be capable of sending 200 fields of info however, the software, DMS, IMS, website host etc. might only post 100 of those fields or less. Make sure the software apps that you use are capable of posting, at least, a majority options data.
Many times if a dealership requests alterations, as Jeff mentioned above with HomeNet making revisions to accomodate ADP, a software company will make the changes you need, don't be afraid to ask.
2) Data collection is still very much a hands on process. Usually this task is delegated to the vendor or individual responsible for producing the window stickers and taking photos.
A vendor should be familiar enough with their software to know fields/options that are not decoded and be sure to note those options in the appropriate places.
The responsibility of these vendors has gone from - photos, data collection and window stickers to - photos sometimes, data collection never, (most are completely dependent on decoders), and window stickers when you complain about not having any.
Hold these vendors to a higher standard, tell them what you want. If the vendor doesn't produce I'll bet there is another vendor out there that will and probably at a better price.
If you are doing photos, data collection and window stickers in-house, unless you have two cracker jack associates both on long contracts, find a vendor.