I wont argue that its not a nice feature, but if the Cisco platform is the only one that has it, it can't be a very well known or requested feature. Since I have never had a customer request it, and in the years of being the project manager for trixbox CE we never had a feature request for it, I can't imagine that you would lose potential business from not having it unless you are trying to replace an existing Cisco system where the people there actually used that feature. I would even bet that in the vast majority of Cisco installs, that very few people use that feature or it would be highly requested for other products.
None of the phones on the market today support any type of standard such as LDAP and getting them to implement it is going to be very difficult unless there is a proven demand for it. Having been involved with hundreds of installs and it never coming up tells me that it must be a very small niche feature that very few people need, therefor its probably not worth the investment to create it and save a couple of potential sales.
Since you have been selling Cisco, you may have been pushing this as a feature and showing people how to use it, therefor your customers may be using it more than others, but I would bet if you stopped pushing it, nobody would know or really care. For most people who are sitting at their desk, they can just make outbound calls via the 3CX Assistant right from their Outlook Contacts, so why would I need to replicate that feature on my desk phone?
