CPM is a great product in terms of user friendliness, but quite expensive compared to Cisco or Quintum. Setup is so easy that u would finish in minutes and u get a great Support from CPM malaysia for the initial setup. Personally i recommend the product due to the ease of use.
BUT it has interoperability problems with other equipment, it ineteroperates with cisco but only at certain settings… like it doesnt support Fast start and things like that… and supports only G723 codec