Pay attention to its provisions for and frequency of updating. Microcomputer-based frontend software requires your initiative and expense to update and your faith that the company will exist when future updates are needed. One exception for the atheists out there is PC Netlink which supports updating by the searcher. The existence of a product newsletter indicates strong support by a company. Exceptional examples include Paperchase which informs the Medline searcher of the appropriate controlled vocabulary, and ProSearch which informs the searcher of the appropriate database-specific field suffixes and prefixes.
Few products offer such database-specific advice.
Database selection assistance is supported on several products. EasyNet, a gateway system, routes your search strategy transparently to a particular database service and database after asking for your subject field. All three types of user friendly searching products offer advantages for certain applications. Menu-driven search systems may attract infrequent searchers who will not get a knowledge of commands reinforced through continual use. Similarly a common menu or command system to access two or more database services simplifies searching greatly e.g. SciMate Searcher, ProSearch, and EasyNet.