Ease of implementation and flexibility to hold the business logic are the most valuable features.
We have used webMethods because of its ubiquitous nature to talk to various technology platforms. Also, the solution had a finite life, webMethods provided a quick integration solution since it is relatively easier to implement, and also, it can hold the business logic in itself.
The client was planning to go in for a separate data exchange platform/Business Information Warehouse as a large-scale global project slated to be alive after five years.
It helped to improve the efficacy of production planning to the market demands and it has improved the quality due to faster information on quality issues.
Mostly, an improvement is needed in the product's documentation.
The documentation deficiencies were in the following areas; since it has been a while, I could recall the top instances where the escalation reached to my level.
wM SAP Adapter User Guide - Example, like Message Broker setup was unclear, leading to issues during Testing and we had refer the internet forums to understand that there is a Message Broker Cleanup utility and that needs to be setup as well.
Release Notes: Used to cover only the latest update for the SAP changes. What has been done to the older version (SAP R/3 4.6, etc.) were not mentioned.
I have used this solution for nearly a year.
In 2008, the technical support's response time was much longer than expected.
There was an implementation issue, i.e., some of the preconditions were not clearly mentioned, so we had to dig through multiple options to troubleshoot and find the right steps.
It was an Enterprise license and I am not sure of the current status.
Put the business first, consider the business architecture and requirements before deciding to go with webMethods. Today, there are multiple open-source, cheaper solutions like Talend available and we can consider those as well.