Gaz,
I have a love/hate relationship with OPS.
We use it strictly as a B2B, corporate branding, rules based ordering system. So I don't have to worry about any of the retail stuff. I currently have 4 of my customers set up on the site comprising some 900 products and 90 templates between them. This is the only system I have used, so I can not give a fair comparison to any others out there. I should also say that I am not using this as SAAS, it is installed on my server which I feel gives me a bit more leeway.
On the positive, for my needs, the software does its job. I find it fairly easy to set up templates for forms data entry. Since I have direct access to the data, I built my own back end for processing the orders. Now with a click of a button, all files can be downloaded, imposed, sent to the appropriate device without any other user intervention. I also have the ability to update the files on the system through ftp. This was important to me as I have a customer that has a couple of hundred price lists that update weekly. If I had to update these by hand through the ops system it would be a huge undertaking. Now, the customer just sends the files to an ftp folder, an applescript checks the files, creates the new thumbnail and updates the files on the system in the background.
On the negative, some things just don't work like they are supposed to or only half work. Updates to the system are slow. I find that support is very lacking. New functionality added in an update can break things that used to work, and it is like pulling teeth to get it fixed. The database structure can change when an update is installed, with no documentation to explain the changes. The database schema is a mess.
Outside of the online support, there is very little out there to help with this system. I tried to start a user group which failed. Mainly because I don't know how to run one. There is a group on linked in that I thought would really take off. But since the creator of the group left, it seems to be dying a quite death. I do wish that more of the people that have this system would band together. I also wish that the ops help system was open. I can not see, or help any one else on the system, only my questions. I feel the users would greatly benefit from other users experience.
Bottom line would I recommend this software to my boss again after working with it? Probably, but only because it is one of the few that are available as a non SAAS.
Is it better or worse than any other of the systems out there? I have no idea.